INTERESTING WORKS

PERSISTENCE OF TOUCH DNA ACCORDING TO THE TIME ELAPSED AND THE AREA OF DEPOSITION

Touch DNA is a research that is nowadays carried out almost systematically. If the loss of genetic information seems obvious when time passes, the authors specify that if the quantity decreases, the number of alleles remains constant. And they indicate that according to the site of analysis (A:torso of a T-shirt or B:buttocks of a pair of pants) the results differ and that beyond 6 hours the minor contributor is no longer visible in a mixture found on the buttocks of pants (The impact of deposition area and time on Touch DNA collected from fabric, Forensic Science International:Genetics Supplement Series).

CHANGE OF COLOR OF THE BLOODSTAIN

The authors share with us the results of their work on the aging of bloodstains for 48 hours and the subsequent color change. They note that the color stabilizes from the sixth hour (IJRP, 2022, 92(1):pp 569-581). This work reminds us that in the open air hemogobin oxidizes into methemoglobin before decomposing definitively into hemichrome and shows us that beyond the sixth hour, the color of the stains no longer allows us to determine the time of deposition of this bloodstain on the support where it will be found.

INSECT STAIN CLASSIFICATION

The authors study several publications concerning insect stains. Their study allows to put forward that the origin of these bloodstains result from regurgitations, tarse prints, translocation or insect defecatories. They propose their classification according to different ways, associated or not, such as visual, contextual, SEM, immunological or molecular methods which will be used according to the samples and conservatives or not approaches (AJFSFM, 2022, ‘(1): pp 43-51). If their study allows a better understanding of how this type of bloodstains is made, several of the proposed methods cannot all be used on site and the contextual method requires a biased approach. This leaves the visual method, which requires that everyone knows the morphological criteria that discriminate this insect trace from the spatter, which is the closest bloodstain morphologically.

IMMERSIVE TECHNOLOGIES IN FORENSICS

The authors have carried out a systematic and critical analysis of 258 articles on the subject of 3D that have been published over the last 17 years (Digital Object Identifier, 2022, vol 10: pp 88821-88857). This huge work allows us to advance in the technologies used without reliving the difficulties already encountered. These immersive technologies (3D modeling, AR, VR, MR…) are coming to forensics and bring many facilities. However, they include problems of impartiality and confidentiality that will have to be solved before they are widely used. 

IMPROVE OUR FORENSIC REASONING

The authors describe how characteristics of human reasoning and situations can contribute to errors and highlight ways to develop procedures to reduce and improve the accuracy of our analyses (Forensic Science International: Synergy vol 4, 2022). While impartiality is desired by experts, we are still subject to situations that can bias our analyses in spite of ourselves. We must continually seek ways to ensure that our results have integrity. 

BEHAVIOR OF A DROP IMPACTING A SLOPED SURFACE

The authors share with us the results of their work on the impact of a drop of water on an inclined surface. They describe 3 successive phases where inertia at the moment of impact leads the first two phases while gravity becomes the main force in action in the third phase (Langmuir 2021, 37 (46) : pp. 13737-13745). This study allows us to better understand how the ovoid shape of a stain is built after the impact of a drop on a inclined surface. 

LATENT BLOODSTAIN DETECTION

The study conducted by the authors highlights Luminol as a method of detecting latent bloodstains after having compared it to forensic lights (Occult bloodstains detection in crime scene analysis, Forensic Chemistry, vol 26, 2021). However, I persist in asserting that this search for latent bloodstains must necessarily be preceded by a search for visible bloodstains, and on the dark surfaces used in this study, I recommend an infra-red observation.

CLASSIFICATION

The organizers of this training introduce learning machine in the classification of bloodstain patterns (A novel, date-driven approach to the classification of bloodstain patterns). It seems obvious to me that we must follow this path. However today we are too few to defend a classification based solely on recognized morphological criteria and which is the essential basis for the introduction of a learning machine. And the authors seem to confuse classification, determination of trajectories and even the analysis that follows. Confusion which is still too common today and which prevents many colleagues from correctly separating these steps and from concentrating on the analysis which follows the classification. Separation which also ensures better impartiality in our methods. So I share the authors’ desire to introduce learning machine, but in a method where the different steps are well separated. Learning machine yes for Classification but not for Analysis.

INSECT STAIN

The author shares with us his observations on the feeding behavior of Calliphora vicina Robineau-Desvoidy, 1830 (Differential restons of adult Calliphora vicina to dry bloodstains on porous versus non-porous surface materials, Forensic Science International, vol 328, nov 2021) belonging to the first squad of necrophagous insects. It indicates that this fly in the adult state partially consumes bloodstains on non-porous surfaces. I would have preferred to obtain information on the edge characteristics of the bloodstains resulting from this partial consumption to help us identify this pattern of bloodstain, but this behavioral study remains an interesting first point of study.

TO BE BETTER

The authors give us the bases on the likelihood ratio (LR) and propose to introduce it in Bloodstain Pattern Analysis (Using the likelihood ration in bloodstain pattern analysis, Journal of Forensic Sciences, 2021). This high quality paper, as is often the case for these three authors, seems to me to be irrelevant. Taking all the necessary precautions, they point out that the discipline lacks guides on how to formulate conclusions in BPA. This is an observation that I share and which makes the application of LR secondary in my opinion. Indeed, the lack of method is so glaring that we do not agree on the goals of the BPA. What the authors of this article take from the most prolific North American authors is that the discipline aims to (1) determine the 3-dimensional origin of bloody spatters, (2) evaluate movement in space of a source of blood, (3) classify bloodstains, (4) assess the amount of blood lost, and (5) assess when the trace was produced. These actions exist at least for the first three BUT are not the goal of BPA but rather the data which will allow to give information on the course of bloody events in the area where the stains were discovered. The question answered by the BPA is why the trace is where we find it. Its identification, its trajectory and the movement from which it can come are information that will allow us to propose an event, they are not the analysis. So when we see this confusion about the goals of the discipline and the lack of guidelines for the formulation of results, the introduction of LR seems very early. As proof of this, the authors must speculate on the future of the discipline with the discovery of a method that can be transposed into the field concerning the dating of traces of blood to give an example of the use of LR. It is obvious that this evaluation is interesting but other much more important developments seem to me to be priorities like the accreditation of methods that I have voted for for years. This accreditation requires that each expert develops a method which allows to articulate his reasoning but also for the Prosecutor, the Defense and the Jury to have a real critique of the results obtained.

BACKSPATTERS

The study carried out by the authors confirms the study that we carried out in 2007-2008 highlighting the phenomenon of cavitation as the origin of the backspatters. They deepen the study of the phenomenon by providing information on the shape of the jet with at least 4 different weapons tested (Study of backspatter using high-speed video of experimental gunshots, Forensic Science, Médecine and Pathology, 2021, 17, pp. 36-46). Mathematical models can now be made to see the dispersion and distribution of these bloodstains. It would be good to test it and complete it by giving information on the size and shape of the backspatters to allow us to identify them.

BLOOD TRACES – INTERPRETATION OF DEPOSITION AND DISTRIBUTION

Blood traces – Interpretation of deposition and distribution de Peter R. de Forest, Peter A. Pizzola et Brooke W. Kammrath, John Wiley & sons Ltd edition, 2021, 348 pages.

The main principle of exchange attributed to Edmond Locard reminds us that “[…] no one can act with the intensity that criminal action implies without leaving multiple marks of its passage […][1] ”.  Of all the type of marks that may be present at a crime scene, bloodstain is probably one of the most common when that involve acts of violence. So, bloodstain must be of interest to the crime scene technician and the forensic scientist.

The announced goal of the authors is to emphasize the need for interpretations to be made by experienced scientists with strict adherence to the scientific method[2]. Thematic that they develop throughout the 15 chapters of their book while focusing on their discussion on three topics: (i) determining the relevance of blood traces (ii) the limitations of the value of a classification scheme, and (iii) a lack of appreciation of the complexity of blood trace interpretations and the necessity for a scientific approach, which often manifests itself as deficient educational requirements for those doing this work[2].

From chapter one: Physical Evidence record, the authors ask the question: Art or Science or both about the reconstruction of past incidents from physical evidence record developing the interest of always relying on a scientific method. Scientific principles from which the BPA moved away from its origins when Kirk indicated in 1967 that the potential of bloodstain configuration was a neglected area of forensic sciences.

The four following chapters first discuss the Physics of blood and then the observation, classification of bloodstains and the impact on a surface of a blood droplet after being in motion in air before the chapter 7 in which they develop eight principles of bloodstain interpretation. Principle #1: – Properly recognized and understood, blood traces may reveal a great deal of useful information during a crime scene investigation. Principle #2: – There will be cases where extensive blood traces are present but where a clear understanding of them does not address relevant issues in the case at hand. Principle #3: – The extent of the blood traces observed at the time of a crime scene investigation is commonly greater than that produced at the time of the initial wounding. This may seem like an obvious statement, but errors are made when this is not given proper consideration. Of course, the time of the initial wounding is often of the most interest in crime scene reconstruction. Principle #4: – The initial wounding may not produce any immediate or useful blood trace configurations. Principle #5: – Blood traces produced in the course of the initial wounding may be altered or totally obscured by the flow of additional blood from the wound. Principle #6: – Blood shed by the wound or wounds may be transferred by post- event activities that may alter or obscure the blood trace geometry associated with the initial wounding event. Principle #7: – Configurations of blood traces consisting of a collection of airborne droplet deposits can be informative with respect to providing an understanding of events that have taken place at a crime scene. Although schemes for assigning such patterns to specific causes or production mechanisms can be helpful, they are often oversimplified. It is naïve to think that patterns encountered in a crime scene can always be assigned to one of a finite number of mechanisms as defined by a typo- logical or taxonomical systems. Principle #8: – A collection of a few seemingly related dried blood droplets is not necessarily a pattern. It should never be treated as one. The number or extent of blood traces may be inadequate to allow a meaningful interpretation.

While the question remains about the scientific nature of forensic science[3], the authors stress in Chapter 8 that the lack of a scientific method can lead innocent people to jail to tackle in the following chapter the modes of practices and qualification of most of the BPA practitioners pointing out the insufficiently rigorous qualifications regarding the need for fundamental scientific knowledge and standards. What they tend to demonstrate by the twelve real cases developed in chapters 10, 11 & 12 in in which misinterpretations are evident and where experts have gone far beyond the request as other papers have already pointed out[4][5][6].

The chapter 13 demystifies some widely held misconceptions existing in BPA which tends to demonstrate lack of appreciation of the complexity of blood trace interpretations that existing BPA associations as well as literature and training do not address.

To conclude, the authors look to the future, emphasizing the use of science and the presence of scientists in crime scene investigations. If SOPs are essential, they must be able to be adapted to the studied crime scene as only those who have a scientific background are able to do it. The same are most suitable for dealing with possible biases and developing hypotheses from bloodstains. As for current publications, they focus on details of the discipline while a solid foundation for interpretation still does not exist. Therefore, scientists and technicians must work together after having clearly identified each other’s limitations. And this scientific culture will bring transparency to the analysis that will lead the expert to communicate with both the Prosecutor and the Defense. Therefore, minimal training should be required for crime scene technicians because it is negligent to merely focus on doing the job right, the emphasis should be on doing the right job.

If I validate most of the observations of the authors, I am sorry that they focused on the Bloodstain patterns analysts in the United States because at least some from the old continent as me propose a way of doing things that comes close to their recommendations[7]. This book remains an important work which I hope will enable most BPA practitioners to change their approach and conduct their analyzes with complete impartiality to go through BPA practitioner to BPA expert.

[1] Edmond Locard : L’enquête criminelle et les méthodes scientifiques, 1920, Flammarion

[2] Peter R. de Forest and al: Blood traces – Interpretation of deposition and distribution, 2021, Willey

[3] Frank Crispino: Le principe de Locard est-il scientifique ? Ou analyse de la scientificité des principes fondamentaux de la criminalistique, 2006, phdthesis Lausanne University

[4] National Research Council of the National Academies. Committee on Identifying the Needs of the Forensic Science Community. Committee on Science, Technology, and Law Policy and Global Affairs. Committee on Applied and Theoretical Statistics Division on Engineering and Physical Sciences (2009). Strengthening Forensic Science in the United States: A Path Forward. Washington, DC: The National Academies Press.

[5] Suzanne D. Tullo : Bloodstain pattern analysis, the Good, the Bad, and the Ugly, Law School Student Scholarship, 2021, 1116:pp. 1-26

[6] R. Austin HIcklin & al: Accuracy and reproducibility of conclusions by forensic bloodstain pattern analysts, 2021, Forensic Science International, 325

[7] Philippe Esperança: Morphoanalyse de traces de sang – Une approche méthodique, Presses Polytechniques et Universitaires Romandes, 2019, 146 pages

ALWAYS TRY

The author of this master’s thesis (http://eprints.bournemouth.ac.uk/35111/1/HANSLIP%2C%20Connor_M.Res._2020.pdf) studies the consequences of the environment on bloodstains present of clothes found buried. His results show that soil pH and bacterial activity are the most important factors in the persistence of bloodstains on clothing and that cotton promotes this persistence. Beyond these results, the author demonstrates that whatever the conditions for finding an evidence, you must always try. You have to be realistic to avoid false hopes BUT even if clothes are found in poor conditions, it is still possible to find clues such as bloodstains on them even though bloodstains are deemed to be easily degraded. So thank you to the author!

AVOID THE WORST

The author based her thoughts on the cases of Julia Rea, David Camm and Joe Bryan who were first convicted and then exonerated to demonstrate that BPA can be devastating, even comparing the field or at least its accuracy to a Ouija board (Bloodstain pattern analysis, the Good, the Bad, the Ugly, 2021). It has been shown that the BPA experts in these three cases went well beyond what fields and their method allow them. Without accreditation of their method, using their notoriety and their CV they imposed their conclusions by putting forward mathematical bases. Let us not forget that the sciences used make it possible to understand the behavior of blood or even to calculate trajectories but are no longer there when it comes to analyzing the results obtained to highlight why bloodstains studied exist. We have to dissociate the classification and the study of trajectory which are the technological tools on which the analysis is based. They are not the analysis. And I join the author of this panmphlet when she compares BPA to an Ouija board since the technical bases of BPA will not be scientific and the analysis methods will not be accredited.

REVIEW OF SOFTWARES USED FOR TRAJECTORY ANALYSIS OF BLOOD SPATTERS

The authors carried out extensive bibliographic work to identify the software used for the trajectories calculation of blood spatters (Forensic Science International, Software for the trajectory Analysis of blood-drops: a systematic review, online 8 sept 2021). And based on these publications, they checked if any validation work was known and should validate this software according to the ANSI / ASB quality system. I would have preferred the same study according to the international standards proposed by ISO because those of the ANSI / ASB, close, are not international. The result remains edifying and I would like to thank the authors for this important work which shows a real desire for improvement. Many of this software have poor or no validation documentation. With regard to robustness, that is to say in borderline situations, the software is not tested while the real world often places us in these borderline conditions where the roughness or porosity of the supports alter the shapes and therefore the calculations. and, while software takes it for granted, it cannot be verified that all the bloodstains on the same wall are really on the same plane or that the bloodstains on two walls are indeed on two orthogonal planes. This is why for a long time, I advise to abandon these software to focus on the locations of the areas of convergence and the dispersion of the blood spatters to determine the location of the blood source when the violent action occurred.

EFFECTS OF YARN SIZE ON BLOODSTAIN IN TEXTILE

I remember the words of a lawyer during one of my testimonies during a criminal trial telling to one of his colleagues “There are certain obvious facts that it is good to explain”. And this paper is an example for me. It is extremely relevant to find bloodstains on the clothes worn by people involved in misdemeanor or criminal acts. However, it is particularly difficult to explain why these bloodstains soil this garment. Intuitively, we can think that many parameters including porosity influence the shape and size of traces on a garment making it difficult or even impossible to identify the bloodstain and therefore its analysis. And the authors of this article (Journal of Forensic Science 2021 Jul, 66(4):1246-1256) reinforce this sentiment by concluding that all bloodstain of their study have been highly altered due to the wicking in textiles whose speed and the area depend on the size of the yarn. This is why I think it is extremely important to look for bloodstains on clothes but that we must be very careful about the explanation of their presence on this fabric.

SPATTERS

While I remain skeptical about the study of traces of blood on clothing, even very reluctant when it comes to spatters, the authors provide us with important information concerning the dispersion of the spatters resulting from a percussion according to their sizes (Experimental study of how far blood spatter stains on fabrics can be found from the blood source, and relevance to Crime Scene reconstruction, Experiments in Fluids 62, 87 (2021). They confirm that the thickest spatters are those which go the farthest, specifying that this distance is about 7m.

SWABBING DNA

The authors share with us the result of their studies (Enhanced forensic DNA recovery with appropriate swabs and optimized swabbing technique, Forensic Science International: Genetics, online March 2021, 102491) indicating the best technique for swabbing invisible DNA with the best type of swab. They highlight an inclination of 60 ° and to rotate the swab during sampling. As far as wood is concerned, they recommend to wet the swab. heavily before its use.

BACKSPATTERS

If the existence of backspatters is established and their mechanism of creation seems known, only few information allows us to establish their behavior. The student, author of this MASTER thesis (Influence of muzzle gases on blood droplet backspatter – Iowa State University), proposes models of the observed behavior of these backspatters including the effects of muzzle gases whose action was at least visible on high speed video accessible on the net. This study allows us to better understand a bloodstain whose mere presence on a suspect is today extremely incriminating. This report, the entirety of which will not be available until July 2021, should allow us to better explain the presence of these bloodstains on a studied surface.

AGING BLOODSTAINS

The authors share the result of their work concerning the dating of traces of blood (A new forensic tool to date human blood pools, Scientific reports 10, N° 8598 (2020)). Based on the phenomenon of evaporation which occurs on fresh bloodstains, they conclude to be able to date the deposit of blood. However, this work was carried out under constant and known humidity and temperature conditions. But in the real world, these conditions are unknown and there is nothing to confirm that they are constant. If we can measure them during the investigations, they only remain valid for this moment and nothing says that they were the same a few minutes before our intervention. This is why I must indicate that this new method is added to others already existing and that, unfortunately, it does not allow more than the others to solve the problem of the dating of traces of blood in an uncontrolled situation such as a crime scene.

INSECT STAINS ON FABRICS

As the authors indicate, the Insect stains are well known to Bloodstain Pattern Analysts. However, they remain difficult to identify whatever the medium studied and we have only a vague idea of their origin. The work carried out makes it possible to better understand the origin of these Insect stains and to have some identifying information when they are observed on clothing (Characterization of Insect stains deposited by Calliphora vicia (Diptera:Calliphoridae) on shirt fabrics, Journal of Medical Entomology, Vol 57 (5), September 2020).

AGING BLOODSTAINS

Estimating the time of presence of bloodstains on an crime scene is a “Holy Grail” which many teams around the world have seized using very different methods. This Malaysian team has come forward with Attenuated Total Fourier Transform Infrared Spectroscopy (ATR-FTIR) and chemometrics (Estimation of the age of bloodstains on soil matrices by ATR-FTIR spectroscopy and Chemometrics, nov 2019, International Journal of Innovative Technology and Exploring Engineering, Vol 9(1), pp 4750-4755). Under these barbaric names, hides an association between an infrared spectrography technique allowing to verify the chemical bonds of the sample quickly and without altering it (University memories) with mathematical and statistical tools applied to chemical data. Unfortunately, like ALL other techniques, it requires further research before it can be considered for use on real scenes where the conditions of temperature, humidity, light are unknown and probably fluctuating.

EXPERIENCE

The authors of this article (Journal of Forensic Sciences, January 2021) tell us that an experienced BPA practitioner commits less error in classifying bloodstains patterns. They even use static tools to establish this evidence. I only read the abstract of the article because it seems to me so much more important to establish how practitioners, experienced or not, classify patterns: which method, what criteria so that we can both understand and check their results. This is much more important and could also answer to the relevant issues raised by the judicial authorities of some US states. The lack of method and therefore of clarity of the American method commonly used throughout the world is a real problem that must be corrected. I think a framed ISO accreditation would be much better to respond to this situation than this type of paper.

LOCATING A BLOUD SOURCE

The authors share with us the results of the validation tests they carried out on their AnTraGoS software to locate a blood source following beating (Testing and validating AnTraGoS algorithms with impact beating spatters, 2020). The equation well known to Bloodstain pattern analysts where the sine of the angle of impact is equal to the width / length ratio of the ellipse associated with the bloodspatter is refined within the framework of a statistical approach. This work taking into account the uncertainties of calculation allows AnTraGoS to give positions of the blood source which are robust in the three dimensions. Even if today I prefer other methods to position a blood source than calculus, I admit that I would like to test AnTraGoS.

BLOOD IDENTIFICATION

The authors of this article (Significance of Blood and its Identification: A Perspective in Forensic Investigation, Vighyan Varta, 2020, vol. 1(7), pp: 5-9) summarize the two stages of the identification of the bloody origin of a trace. This situation regularly leads to confusion during trials. As the authors indicate there are two types of tests, presumptive and confirmatory. Presumptive tests are very numerous, some produce a color (eg green for LeucoMalachite Green, purple for LeucoCrystal Violet …), others fluoresce like Fluorescein or produce a light called chemiuminescence like Bluestar. This list, far from being exhaustive, is intended to guide a sample by indicating the possible bloody origin of the reacting area. This means that a positive reaction to one of these tests does not allow us to conclude that we are facing a trace of blood. Only confirmatory tests such as the Takayama Crystal Test and the Teichmann Crystal Test allow us to conclude in this direction, that is to say that we are dealing with blood.

FORENSIC DNA PHENOTYPING

This book discusses the added value in forensics of the study of DNA phenotypes. It is true that the coding parts of DNA provide information on the size and predisposition to male pattern baldness, but also on the colors of the iris, hair and skin and potentially on facial features. However, some of this data can be modified or altered so that what we see (phenotypic expression) no longer corresponds to what is genetically encoded. This is the case with the color of the hair, that of the iris, the features of the face and even the color of the skin. Thus these analyzes, like all forensic analyzes, remain information and not the truth. However, by their nature, the source of this information raises legal and ethical barriers that the authors of this chapter (Forensic DNA Phenotyping: Principles, applications and advancements, 2020, chapter Forensic DNA Phenotyping pp. 547-559) propose to resolve by an appropriate and regulated methodology.

BLOODSTAIN PATTERN ANALYSIS

In his paper (Manchas de sangre y sus soportes. Cambios morfológicos de los patrones, Gaceta Internacional de Ciencias Forenses, 35, Abril-Junio 2020) the author gives general and objective information on the Bloodstain Pattern Analysis. He indicates the goals of this discipline while specifying its limits and the difficulties of analysis by relying on his study of the existence of a Drip stain on different media.

PATH DETERMINATION FROM BLOODSTAINS ON CLOTHES

The student who conducted this master’s 2 work (The Wicking of Blood in Fabrics and the Effect It Has on the Angle of Impact, Master’s Thesis, University of Central Oklahoma Forensic Science Institute, Spring 2020, Proquest 27832117) concludes that the calculation methods used on soft and non-porous surfaces are also valid on clothing, never causing more than 5 ° error. While this work can provide information, it does not solve the real problem of calculating trajectories on clothes. This work therefore makes it possible to calculate a trajectory, but how can we know the exact position of the garment to establish where this trajectory takes us. It would be necessary to know with exactitude the position of the part of the covered body but also as the garment was worn, raised, turned … And if the fabric is not worn that it was its exact position. It is this problematic which for me is insoluble which leads to nullify any calculation of trajectories of bloodstains on clothes.

CREATION OF BLOODSTAIN ON FABRICS

The authors share with us their work concerning the fundamental study of the formation of a drip bloodstain on a fabric (Fundamental Study of Porcine Drip Bloodstains on Fabrics: blood droplet impact and wicking dynamics, Forensic Science International 25 nov 2020). They determine that the impact and wicking processes are classified into four stages which they name: 1. initial impact, 2. initial absorption, 3. first wicking, 4. second wicking. They conclude that the size of the stain is dependent on the two wicking steps, using the term alteration. While this study is of intellectual interest, it confirms my inclination to be extremely careful about studying bloody clothing without study of crime scene. In fact, the #Bloodstain Pattern Analysis is based on the observation of morphological criteria such as size, shape and others and these two first criteria are altered by the absorption capacity of the fabric. This makes it difficult to conclude on the mechanisms creating traces studied on clothing.

BODY FLUIDS IDENTIFICATION

Following the work of Muro et al. (Forensic Chem 2016, 1, 31), the authors have developed a model of identification of stains of urine by RAMAN in addition to the already existing models concerning blood, saliva, sperm, sweat, vaginal fluids (An universal test for the forensic Identification of all main body fluids including Urine, Forensic Chemistry, online may 2020). Their work therefore provides a robust, non-destructive technique for identifying body fluids. The problem remains that RAMAN is a spectroscopy method requiring a heavy platform. When will a method, universal like this, but usable in the field?

AGING BLOODSTAINS

The two North American authors offer us an exhaustive list of the methods of determination of bloodstains time since deposition since 1907 (Crime clock – Analytical studies for approximating time since deposition of bloodstains, Forensic Chemistry, vol 19, June 2020 ). This overview shows that today, regardless of the method developed such as hemoglobin degradation, the use of RAMAN or more recently smartphones, none can answer this crucial question: how long has the blood is present on the support studied?

BACKSPATTERS PHENOMENON

If the backspatters are well known by the BPA community, it is quite different for the phenomenon which creates them. In 2012, Aurélien Rubio, one of my students, studied this phenomenon. His work led to this paper “Backspatter simulation: comparison of a basic sponge and a complex model” (Journal of Forensic Identification 64 (3), 2014, pp. 285-303) and to this presentation (https://prezi.com/kftlxq46ajir/backspatter-phenomenon-iai/) that I did at the IAI meeting (2013) and the IABPA Europe meeting (2013).

FROM THE DROP TO THE STAIN

Our job is Forensic, so we apply techniques to evidences to determine the facts and identify the protagonists. The goal of Bloodstain Pattern Analysis is to “use” the edge characteristics of bloodstains to determine what may have produced them. For years, the analysts have worked empirically, ignoring the phenomena in action while arriving at correct conclusions more often than not. Today, it seems to me essential to make knowledge of work of mechanics of the fluids allowing to better understand the phenomena in action. If my work remains a simple approach (Morphonalyse de traces de sang – Approche méthodique, 2019), the thesis of Natalia Kabaliuk (Dynamics of Blood drop formation and flight, New-Zealand, 2014) and the publications of AL Yarin (Drop impact Dynamics:splashing, spreading, receding, bouncing…, 2006), M. Bussmann & al (Modeling the splash of a Droplet impacting a solid surface, 2000) and recently of M. Qin (Sub-patterns of tain sheet splash on a smooth surface, 2020) allow us to get as close as possible to the forces in action creating the drop and then the stain.

THE ERROR IN FORENSIC PRACTISE

The book “Mistakes, errors and failures across Culture” presents in its part VI a chapter on the error in forensic science
Errors and Failures in Forensic practice,  In: Vanderheiden E., Mayer CH. (eds) Mistakes, Errors and Failures across Cultures. Springer, Cham, Online ISBN 978-3-030-35574-6
Its author poses a real situation which the consequences can be disastrous for the criminal trial. This is why reading this chapter will certainly allow us to verify our personal situations and to amend ourselves if necessary, to continue to serve justice as well as possible.

SIZE AND SPEED OF SPATTER

The authors share with us their observations as to the size and the speed of projections following a blow but also following a ballistic shooting (.22 caliber).
Connecting In-flight drop measurements to blood spatter, 2020
While these data may be relevant for estimating the path of spatters following a blunt wound, they are insufficient with regard to the ballistic wound. In fact, backspatters are not limited to spatters from the entry of the bullet. Other spatters are then produced in response to the phenomenon of cavitation produced on the organs by the bullet and it is essentially the latter which are seen by BP analysts. This is why blood “encapsulated” in a cylinder is not enough to observe the whole complexity of backspatters.

AREA OF ORIGIN ANALYSIS USING FARO ZONE 3D

The authors use the FARO Zone 3D tool to locate the area of origin on various wallpapers (Accuracy of area of origin analysis on textured, wallpaper surfaces, JBPA, 35 (1), 2020).
This tool like BackTracks Suite®, HemoSpat® and all their variants produces linear trajectories for the spatters studied while the real paths are parabolic. This extrapolation is correct for a birdview which allows the calculation of (0x) and (Oy). It is however no longer correct for a sideview or rearview which allow the calculation of (Oz), the height. This first error explains that in the practical case presented, for a small distance of 45cm, we already have errors of 7.10 to 15.49cm for the Height. At the same time, these tools all assume that splattered surfaces are perfectly flat, perfectly vertical and horizontal and that an angle of 90 ° exists between these surfaces. Hypothesis which is never verified by the technicians and which even seems to me unverifiable in the field. However, if this hypothesis turns out to be incorrect (which is frequent), the location could be quite different without being able to calculate it since we have no information on the true situation of the splattered surfaces. This is why the apparent precision that these tools, including FARO Zone 3D, could give, seems really dangerous to me. Even if they are more handwork, visual methods and used in-situ seem to me much more accurate for the calculation of the Height (Oz) which remains the most important data for Justice.

BLOODSTAINS AND IR

The authors confirm by their study that the Infra-Red is the best method to find traces of blood and that on very varied fabric
A study of the mid-infrared emissivity of dried blood on fabrics, Forensic Chemistry, march 2020.

LATENT FINGERPRINTS ENHANCEMENTS

The authors make an inventory of the highlighting of latent fingerprint techniques. Very educational, this article (Latent Fingerprint enhancement techniques: a review, Journal of Chemical reviews, 2020, 2 (1), pp 40-56) explains the implementation of chemical techniques but also what a fingerprint is. This review work therefore allows non-specialists to grasp the chemical enhancement of fingerprints and the prospects in nanotechnology.

FINGERPRINT ON HUMAN SKIN

Difficult support, the skin remains a target that we want to study to quickly identify who may have been in contact with the victim. Various methods of highlighting fingerprints on the skin exist but remain little used. The authors (Latent fingerprint on Human Skin: a silent diagnosis, Journal of Forensic Science & Criminology, 2019, vol 7 (2): 205) take stock and highlight Cyanoacrylate and Ruthenium tetroxide (RTX ). They also report difficulties related to the delay between the deposit and its search without forgetting the actions of the body decomposition, weather conditions…

IMPARTIALITY IN FORENSIC WORK FOLLOWING ISO

The authors develop a way allowing to integrate the impartiality required for a long time by the ISO 17020 standard and more recently by the ISO 17025 standard. This requirement of impartiality and independence as the accreditation of our methods by ISO are crucial to demonstrate the expert’s work architecture. As they conclude this demonstration is not simple but not monumental. This is why I invite you to read their publication
(ISO Standards addressing issues of Bias and impartiality in Forensic work, Journal of Forensic Sciences, Dec. 2019).
And I hope that as soon as possible, those involved in the criminal trial will be attentive to the expert’s certifications or even require them.

CRIME SCENE TECHNICIANS

The author of this study focuses on the province of Quebec in Canada BUT the expected skills have to be apply to all technicians regardless of their country of origin. Indeed, the investigations carried out on the scene of crime wherever it is, must respect the local procedural rules and discover the evidences which will make it possible to appreciate the facts and to discover the protagonists
(La criminologie de l’information : état des lieux et perspectives, vol 52 (2), sept 2019: pp193-217).

DETECTION OF BLOOD ON DARK MATERIALS

Australian authors compare Luminol, LCV, TMB and COMBUR Test to find traces of blood diluted 1/100 on different dark surfaces up to 8 hours after deposition. Luminol proves to be the best product for both finding traces and allowing the study of their shape
A comparison of four presumptive tests for the detection of blood on dark materials,
(Journal of Forensic Sciences, 2019).
However, if Luminol is put forward, no information is given on the reaction mixture used.

PCR FOR AGING THE BLOODSTAIN

For his Master thesis, the author shows that the ddPCR (droplet digital PCR) does not allow to age traces of blood mainly because of the method used. However, the author remains convinced that the study of RNA degradation rates remains valid and that it would be better to use qPCR (qualitative PCR).
Estimating the Age of a bloodstain using droplet digital PCR
(Thesis submitted at West Virginia University, 2019).

AVOID CONTEXTUAL BIAS

As a research project of the US Department of Justice, the author presents three approaches to avoid polluting of contextual information the person who leads the expertise
Developing effective methods for addressing contextuel bias in forensic Science
(2019)

DETECTION OF BLOOD ON DARK MATERIALS

Australian authors compare Luminol, LCV, TMB and COMBUR Test to find traces of blood diluted 1/100 on different dark surfaces up to 8 hours after deposition. Luminol proves to be the best product for both finding traces and allowing the study of their shape
A comparison of four presumptive tests for the detection of blood on dark materials,
(Journal of Forensic Sciences, 2019).
However, if Luminol is put forward, no information is given on the reaction mixture used.

FINGERPRINTS

The authors present us an inventory of the oldest discipline of forensic science
GJRA, vol 8 (1), 2019, pp 22-23
Its reading allows the discovery of fingerprints identification, the only technique that today can differentiate each individual including true twins.

BLOOD DETECTION AFTER A FIRE

Thanks to the authors to show us that we always have to be positive. It is not uncommon for places of events to be set on fire to erase all clues. The authors demonstrate that even after exposure to 1000 °, it is possible to find traces of blood with Luminol and especially to extract a complete DNA profile. Result they obtained for 60% of their samples.
Detection of blood and DNA traces after thermal exposure
(International Journal of Legal Medicine, 2017)

HANDLING TIME REQUIRED FOR A TOUCH DNA

The authors studied the required wearing time of a garment to find a contact DNA. They estimate this time at only 2 seconds to obtain a complete profile of the handler. To this result are added the study of 3 sampling methods and how to do this sampling
Scientific Reports 9, 2019, 9542.

USE OF FARO SOFTWARES

The authors compare the latest software sold by FARO to study the localization of blood sources.
Forensic Science International, vol 301, 2019, pp. 166-173.
It must already be taken into account that at least one of the authors is related to the commercial company FARO. Then, if these tools can accurately calculate a distance from a wall, what about the height? Whereas this dimension that remains in my opinion the most important to estimate for criminal prosecution and it is known for a long time that the mathematical method used by these tools does not give a precise value of the Height.

IDENTIFICATION OF INSECTS BLOODSTAINS

Artifacts caused by scavenging Diptera can lead to errors in the analysis of facts that may have occurred on the scene. This is why the confirmaiton test developed by the authors of this article brings a real added value. This test is based on the detection of cathepsin D present in the digestive juices of Diptera
Forensic Science International: Synergy, vol. 1, 2019, pp. 1-10.

3D CAD MODELING

3D CAD modeling allows you to move around freely. The way to move inside is intuitive and is based on the use of keyboard arrows. The insertion of information is infinite and allows for a simple and complete approach of the place of evidences, the results of their analyzes and even a reconstruction of facts.

EXPERT INTEGRITY

This paper reminds me of Talleyrand’s famous sentence: “If it goes without saying it, it will be even better by saying it”. Indeed, the integrity of the expert is obvious but it may be necessary to recall. This is what the authors of this article do by also giving keys to avoid conflicts of interest.
Scientific integrity in the forensic sciences: Consumerism, conflicts of interest, and transparency,
Science and Justice, 2019.

THE GSR

Known for a long time, the use and interpretation of the results of firing residues can sometimes be confusing. The authors propose a complete review of this index. After having defined it, they present how to interpret it and what are its limits
Understanding Gunshot Residue Evidence and its role in Forensic Science,
The American Journal of Forensic Medicine and Pathology, 2019).

WASHED BLOODY TEXTILES…

The authors confirm that washing bloody cotton or polyester textiles does not obliterate the blood test on them. They studied the effects of drying time before washing, the different programmes of the washing machine, the different detergents used and even the drying temperature. They obtained positive results with the use of Luminol or COMBUR solution and even a genetic profile in 28% of these positive cases. Which makes me repeat that the first quality of a person working in Forensics is optimism!
Detectability of bloodstains after machine washing
International Journal of Legal Medicine, online 21 juillet 2018

IS THE EXPERT SCIENTIFIC?

After demonstrating that scientific evaluation standards are not adapted to forensic science, the authors cite some principles that I believe are essential for all experts. They highlight a minimum level of competence, a capacity to question and to express with conviction their analyses.
Are Forensic Scientists Experts?
Journal of Applied Research in Memory and Cognition, Vol 7 (2), 2018, pp. 199-208

PHYSICS OF EJECTION MODEL CREATION

The authors describe the laws of Physics that apply to the movement of traces of blood when handling a bloody object, creating the ejection model well known to all Morphoanalysts. Work that confirms that the main action of the Centrifugal Force leads to the manipulator being slightly or even not bloody as a result of the movements performed. I also hold the PDF of this article.
The Dynamics of Blood Drop Release from Swinging Objects in the Creation of Cast‐off Bloodstain Patterns
Journal of Forensic Sciences, 2018, online juillet 2018)

EXPERTISE IN CRIMINAL PROCEEDINGS

The author of the reflections on the place of judicial expertise in criminal proceedings in adversarial and inquisitorial systems highlights the continental European system. He modulates his opinion by pointing out the excessively close relationship that may exist between the Public Prosecutor’s Office and the experts, the absence of the parties at all stages of the investigation and the impossibility of carrying out a counter-expertise in certain disciplines, as is often the case in Genetics. It also raises the institutional independence that forensic science centres must have and which is not ensured in state laboratories around the world. He cites the IPSC of the University of Lausanne as one of the only centres meeting this requirement of autonomy.
De l’expertise judiciaire dans le cadre du procès criminel et de la recherche de la vérité : quelques réflexions
Revue de Droit Université de Sherbrooke, 1996-1977, vol 27 (1-2), 47 pages)

OBJECTIVE IDENTIFICATION OF BLOOD TRACE PATTERNS

I am pleased to see that some, although they are primarily academics and not practitioners in the field, point to the need for an objective or even automatic method of identifying blood trace patterns. They develop it on impact or ejection models, both of which are composed of projections. It is since 2006 that I have been pointing out that these models are mainly differentiated by the distribution of blood traces, convergent for the impact model and linear for the ejection model. And for almost 10 years I have been using and teaching my identification key, an objective method for identifying traces of blood already well known in the Animal and Plant Worlds.
An automated approach to the classification of impact spatter and cast-off bloodstain patterns 
Forensic science Inernational, 2018, 289, pp 310-319)

DECISION-MAKING BY THE EXPERT

The authors focus on the limitations and vulnerabilities of decision-making under significant conditions of uncertainty. Emphasizing emotional and cognitive biases, they develop the influence they can have on the reliability of forensic results. Finally, they indicate that a scientific basis would be useful in determining the value of evidence and therefore forensic analysis.
Examining the Role of Science in the Courtroom: Admissibility and reliability of forensic science
Albany law review, 2018).

MENSTRUAL BLOOD/PERIPHERAL BLOOD

The authors remind me of a case in which I was involved and for which I was able to differentiate menstrual blood from peripheral blood. They offer the TEICHMANN test. This test is already well known in our environment as a test to confirm the blood origin of the sample, it would give a negative result for menstrual blood. If this result is confirmed, the differentiation would become very simple.
Detection and comparaison of normal and menstruel Blood sangles found at crime scene
International Journal of Current research in Life Sciences, 2018, vol 07 (06), pp2233-2236)

IDENTIFICATION OF 6 BIOLOGICAL FLUIDS

The authors of this article show us the interest of the ParaDNA Body Fluid ID Test. It identifies the nature of six types of biological traces: vaginal fluid, seminal fluid, semen, saliva, menstrual blood and circulatory blood in 90 minutes, they say!
Developmental Validation of the ParaDNA® Body Fluid ID System – A rapid multiplex mRNA-profiling system for the forensic identification of body fluids
(Forensic Science International: Genetics, online 23 août 2018)

HIDING TRACES OF BLOOD!

The authors show us that we must always believe in it. Indeed, despite walls that have been plastered and repainted up to 6 times, it is possible to find traces of blood. To do this, they highlight a preparation of the area to be treated by moistening it before using a Luminol solution. They even obtained DNA profiles in 74% of cases after this preparatory action.
Detectability, visualization, and DNA analysis of bloodstains after repainting the walls
(International Journal of Légal Medicine 2018, pp1-10)

PERCEPTION OF THE EXPERT BY THE JURY

The American and English authors confirm that the credibility of the expert in the eyes of the jurors depends as much on the behaviour and tone used by the expert as on his training and the scientific demonstration of his results.
Jurors’ perceptions of forensic science expert witnesses: Experience, qualifications, testimony style and credibility
(Forensic Science International, online 9 août 2018).

DIFFERENTIATION OF MONOZYGOTIC TWINS WITH THEIR SALIVA

The work of this Dutch team has already made it possible to differentiate identical twins. Today they show that it is possible to differentiate them on their saliva collected by swab or on a cigarette butt.
Investigating the Epigenetic Discrimination of Identical Twins Using Buccal Swabs, Saliva, and Cigarette Butts in the Forensic Setting (May 2018)

SPERM PERSISTENCE DURING WASHING

The study conducted by this Australian team shows that it is possible to find su sperm on soiled clothing despite 6 washes.
A pilot study: The effects of repeat washing and fabric type on the detection of seminal fluid and spermatozoa
(Forensic Science International, August 2018, Vol 289: pp. 51-56)

DEGRADATION OF BLOODY EVIDENCE

We have been hearing for a long time why bloody clues should be allowed to dry, why they should not be stored in plastic bags. The authors explain why and propose the best attitudes to have according to the nature of the bloody support.
Medecine Science International Medical Journal (2018)

DETERMINATION OF A BLOODY INTERACTION

My methodology provides that to determine a chronology between two bloody sequences, I must find at least one interaction between traces of each sequence. The authors offer us a significant help to determine the direction of the interaction between a passive trace and a contact transfer.
Visual characteristics for sequencing of overlapping bloodstain patterns
(Forensic Science International, mars 2018)

BLOOD IDENTIFICATION OF FINE TRACES

It is frequent that technicians cannot verify in situ the blood nature of a trace because it is small and you do not want to lose the possibility of extracting DNA. The authors propose a test in the form of a strip to take the trace. They then use hypespectral imaging to allow contactless identification. This does not alter a subsequent DNA search if it is blood.
The application of near-infrared reflectance hyperspectral imaging for the detection and extraction of bloodstains
(Cluster Computing, feb. 2018: pp. 1-9).

CYANOACRILATE AND CONTACT DNA

Despite the information provided by suppliers PolyCyano UV (Foster + Freeman Ltd) as well as Lumicyano™ (Crime Science technology) are not without effect on contact DNA. Both can cause loss of important fragments preventing the determination of a complete DNA profile.
Impact of One-Step Luminescent Cyanoacrylate Treatment on Subsequent DNA Analysis 
(Forensic Science International, feb 2018).

CYANOACRILATE AND CONTACT DNA

Despite the information provided by suppliers PolyCyano UV (Foster + Freeman Ltd) as well as Lumicyano™ (Crime Science technology) are not without effect on contact DNA. Both can cause loss of important fragments preventing the determination of a complete DNA profile.
Impact of One-Step Luminescent Cyanoacrylate Treatment on Subsequent DNA Analysis 
(Forensic Science International, feb 2018).

AGE DETERMINATION

The authors present a method for age determination in the sensitive 11-21 age group based on calcification of long bone heads at knees and ankles.
Estimation of Age Group (11–21 Years) By Roentgenologic Study of Epiphyseal Fusion of Long Bones At Knee And Ankle Joints
(Journal of Punjab Academy of Forensic Medicine & Toxicology: Vol 17(2), 2017, pp. 80-86).

METHODOLOGY IN BLOODSTAIN PATTERN ANALYSIS

I am happy to read from colleagues, even more academics than in the field, the methodology I have been defending for more than 10 years. Thus, it is finally recognized in New Zealand that access to survey data must be limited to what is strictly necessary and that the person who verifies the results is unaware of the survey. And this organization of work does not require a lot of staff, time and financial resource.
Contextual information management: An example of independent-checking in the review of laboratory-based bloodstain pattern analysis
(Science & Justice, 2018).

HORIZONTAL DISPLACEMENT OF A PROJECTION

While this may seem abstract to some, knowing how far horizontally a trace of blood travels following a percussion is essential information to know the victim’s position during this event. Thus the work carried out by Gareth Liew for his thesis has immediate practical application.
Determining the furthest distance travelled horizontally by impact spatter blood drop
Masters by Coursework thesis, Murdoch University, 2017).

METHODOLOGY IN MORPHOANALYSIS OF BLOOD TRACES

I am happy to read that I am no longer the only one advocating a methodology organized around two themes, Identification and Analysis, which follow one another to make the expert conclusions as objective as possible.
Journal of Forensic Sciences 63 (1), p. 341, 2018.
This organization allowed me to obtain ISO 17020 accreditation in 2014, which no other organization has yet obtained.

FINGERPRINTS ON WASHED KNIVES

The thesis work carried out shows that it is possible to find fingerprints on kitchen knives that have been dishwashed and highlights the techniques that should be used as appropriate.
The enhancement of fingerprints on kitchen knives that have been through a wash cycle in the dishwater (N. Juriansz, 2017)

METHODS OF EXTRACTING SPERM FROM A CELL MIXTURE

This thesis makes it possible to make an inventory of the different methods of extraction of sperm cells from a cell mixture.
Forensic techniques for the isolation of sperm cells from mixed cell fractions
(A review, Murdoch University)

FOOTPRINTS ON FRUITS AND VEGETABLES

Today it is possible to highlight fingerprints on fruits (apple, tomato) and vegetables (onions, potato) with at least three types of powders including simple black powder. If we except the tomato, this highlighting remains possible at least 2 weeks after deposition.
The Visualization of latent fingerprints on fruits and vegetables
(Journal of Emerging Forensic Sciences Research Vol 2 (2)).

CARRIER’S DNA

It is common for the individual identified as a wearer to indicate that he or she has lent his or her clothing to another person and that the latter has not left his or her DNA there. The authors allow us to advance in this thorny issue of determining the clothing wearer through DNA through experience including up to three wearers. And as they conclude, it is extremely rare that we do not find the DNA of a wearer, even if the wearing of the garment was brief, 10min for example.
Impact of several wearers on the persistence of DNA on clothes—a study with experimental scenarios
(International Journal of Legal Medicine, NOv. 2017: pp1-7)

THE BLOOD ON THE CLOTHES

In recent years, various authors have focused on the study of traces on clothing, demonstrating that the alteration by the fabric of these traces makes them difficult to interpret (What we already knew from earlier publications: BRIGGS-1978 KARGER-1998, SLEMKO, 2003). Human obstinacy makes them continue their studies without solving the real problem of the nature of the fabric that damages the outline of the trace and without answering questions, was the clothing worn? if so, by a spectator or an aggressor? And above all, by not taking into account that the morphoanalyst will more seriously study the traces that stain the neighbouring walls of the possibly soiled protagonists.
Chapter Seven – Forensic Interpretation of Bloodstains on Fabrics
(Forensic Textile Science, 2017 : pp127-167)

TRACE CREATION BY A FLY

It is known that flies from the first squads can create traces of blood. These lead to misinterpretation if the morphoanalysts are not sensitive to this type of artifact. The authors suggest that we observe the results of the Lucilia cuprina fly in a house where human blood is available.
Location of Artifacts Deposited by the Blow Fly Lucilia cuprina After Feeding on Human Blood at Simulated Indoor Crime Scenes
(Journal of Forensic Sciences, Nov 2017).

COGNITIVE BIAS

The possibility for the expert to be biased in the rendering of these results is an opportunity that has concerned me for years and has led me to develop methods related to this perspective. This is why I could only welcome the work of the authors, who demonstrate to us through 403 experts from 21 countries that the bias is not sufficiently taken into account.
Cognitive Bias and Blindness: A Global Survey of Forensic Science Examiners
(Journal of Applied Research in Memory and Cognition, Nov. 2017)

ARTEMISININ-SMARTPHONE TO DETECT TRACES OF LATENT BLOOD

The studies conducted show that replacing Luminol with Artimisinin reduces the number of false positives while maintaining a sensitivity threshold of 100,000 and the production of photo documentation by smartPhone.
Artemisinin-luminol chemiluminescence for forensic blood- stain detection using smart phone as detector
(Analytical Chemistry, May 2017)

LUMINOL SENSITIVITY THRESHOLD

The authors calculated the detection threshold for Luminol for blood on cotton at 200,000. Beyond this result, they propose a technique for determining the sensitivity thresholds for all products used in the detection of blood traces.
A quantitative method for determining a representative detection limit of the forensic luminol test for latent bloodstains (Forensic Science International, Vol 278, Sept. 2017: pp. 396-403)

USE OF X-RAY FLUORESCENCE

The authors introduce the use of X-ray fluorescence (MA-XRF) for the detection of human traces and gunshot residue on large surfaces such as complete clothing or walls. This technique also allows in high resolution to give the order of shots with different ammunition. X-rays also make it possible to find an impact signature even if it is covered by multiple layers of wallpaper or blood.
Large area imaging of forensic evidence with MA-XRF
 (Scientific Reports 7, Article number: 15056, 2017)

DATING OF BLOOD TRACES RAMAN METHOD

This work shows the effectiveness of using Raman spectroscopy to non-destructively analyze blood traces, highlighting specific changes over time up to two years. The observed changes in spectra over time were consistent with known biochemical processes that occur when blood ages naturally, and these variations were sufficient to allow differentiation and predictions of time from deposition to 2 years with an overall accuracy of ~70%.
Predicting the time of the crime: Bloodstain aging estimation for up to two years (Forensic Chemistry, Vol 5, Sept 2017: pp 1-7)

AGE DETERMINATION BASED ON BLOOD

If the level of gene methylation is a function of the person’s age, the authors show that from traces of blood, they have identified the level of methylation of selected genes and thus determined the person’s age with a maximum error of 6 years and this over a panel of 82 women aged 18 to 91 years.
Methylation Status and Human Age at ree Autosomal Loci: A New Forensic Pro ling Tool
 (Journal of Forensic and Crime Studies, Nov 2017, Vol 1 (1))

BACK PROJECTION MODELING

A theoretical model describing the distribution of blood spatter resulting from a blunt bullet is proposed based on Rayleigh-Taylor instability (responsible for the sizes of blood drops generated and their initial velocity) and the effects of gravity and friction. Today, this model is theoretical, but I know Daniel ATTINGER well enough to know his desire to discover a model applicable in the real world.
Hydrodynamics of back spatter by blunt bullet gunshot with a link to bloodstain pattern analysis
 (Physical Review Fluids 2, July 2017)

IDENTIFICATION MENSTRUAL BLOOD

Sexual assault is a serious offence and the identification of body fluids related to sexual activity is important. While reliable tests for the detection of semen and saliva exist, the detection of other body fluids, such as vaginal or menstrual fluids, is more difficult. The authors present the validation of an immunochromatographic test that allows such discrimination, the SERATEC PMB test, and its results in real cases. The results show that this test is a real improvement in the analysis and interpretation of evidence from sexual assaults.
Forensic differentiation between peripheral and menstrual blood in cases of alleged sexual assault—validating an immunochromatographic multiplex assay for simultaneous detection of human hemoglobin and D-dimer
(International Journal of Legal Medicine, Oct 2017: pp. 1-8)

DNA CLEAN-UP OF THE FINGERPRINT BRUSH

The fingerprint brush is well known for its potential for cross-contamination between evidence, highlighting the risk of using the same fingerprint brush on multiple surfaces inside and between crime scenes. The authors indicate a method of cleaning these brushes by using a solution containing 1% bleach and 5% Virkon (DNA decontamination of fingerprint brushes, Forensic Science International May 2017)

DOCUMENTATION OF A CRIME SCENE WITH A DRONE

Recent advances in drone technology have not only facilitated its access but also reduced the cost of aerial imagery. The authors show the prospects of 3D modelling with low-end technology based on three simulations of outdoor forensic scenes involving a manikin, skeletal remains and artificial blood were built in an abandoned quarry. The results showed that the tool is effective in searching for dispersed body parts but is insufficient for less easily identifiable evidence, such as traces of blood. These were only detected after they had been properly marked by human action.
Using drone-mounted cameras for on-site body documentation: 3D mapping and active survey
(Forensic Science International, Oct 2017)

ALTERATION OF BLOOD TRACES BY FLIES

The action of flies at a bloody crime scene, feeding on the blood present, regularly leads to misinterpretation by the Morphoanalyst who is not aware of this action. This is why Christopher Dwen conducted his thesis on this subject proposing to add to the morphological criteria already studied, the study of external factors influencing the distribution of traces, the shape and color of each trace. What the experienced Morphoanalysts are already doing (Dwen, C. J.L., 2017).
Alteration of bloodstain patterns by Diptera: objective analysis based on Wonder’s 2001 criteria
(Masters Thesis of Bournemouth University)

DNA TO DIFFERENTIATE IDENTICAL TWINS

While it is known that DNA methylation can differentiate between homozygous twins, the authors show its potential in forensic science.
Epigenetic discrimination of identical twins from blood under the forensic scenario
(Forensic Science International: Genetics, Vol 31, Nov. 2017: pp.67-80)

IDENTIFICATION OF THE INJURED AREA

I had the chance to attend a meeting with Don. J. Johnson and to hear him present us the very interesting results of his team concerning the identification of the injured area from microRNAs contained in the traces of blood flowing from the wound.
A Molecular Method to Detect Wound Cells in Bloodstains Resultant of Sharp Force Injuries for Crime Scene Reconstruction
(Journal of Forensic Sciences, août 2017)

THE BLOOD ON A BURNED SCENE

The perpetrators can set fire to destroy the evidence. It is accepted that blood and especially DNA are no longer usable beyond a temperature of 1000°C. However, following their work, the authors conclude that even after exposure to a maximum temperature of 1000°C, complete DNA was obtained on 60% of the traces. That is why we must pay the same attention to burnt scenes as to others. You always have to look, that’s often how you find it!
Detection of blood and DNA traces after thermal exposure
(International Journal of Legal Medicine, Oct 2017: pp. 1-9)

USE OF RNA TO DATE TRACES OF BLOOD

The authors present their method using mRNAs and microRNAs to date traces of blood. Their results seem encouraging.
Quantification of RNA degradation of blood-specific markers to indicate the age of bloodstains
(Forensic Science International, Oct 2017)

DATING OF BLOOD TRACES

The authors demonstrate that the Attenuated Total Reflection (ATR)-Fourier Transform Infrared (FTIR) technique combined with advanced chemometric methods can be used as a non-destructive and rapid method to estimate the age of blood traces at a real crime scene.
Estimation of the age of human bloodstains under the simulated indoor and outdoor crime scene conditions by ATR-FTIR spectroscopy
(Science Reports, Oct 2017)

THE KASTEL-MEYER (KM) TEST

The kastel-Meyer test also called the KM is widely used in Genetics to confirm the blood origin of the index. This publication shows the deleterious action of one of these components on DNA. This is why this test must be carried out on only part of the unanalyzed trace or else another confirmatory test such as the one proposed by the authors of this study must be used.
Kastle-Meyer blood test reagents are deleterious to DNA
(Forensic Science International, oct. 2017)

BLOOD IDENTIFICATION TEST FOR A TRACE

The authors highlight Green Leucomalachite, indicating that it is the most suitable test to test the blood origin of a sample, with the fewest false positives. They even indicate that LMV should replace Benzedine. I remind you that these two products are highly toxic, today benzidine is only used in France under a hood. If the LMV has few false positives, light is one, which induces a certain reaction in a house for example. It should be added that the reaction medium of the LMV is very acidic, making it very altering for DNA analysis.
Presumptive tests: A substitute for Benzidine in blood samples recognition
(Forensic Sciences International Genetics)

EFFECT OF SURFACE ROUGHNESS ON THE SHAPE OF BLOOD TRACES

The authors aim to explain the impact of surface roughness and wettability on the traces that stain a surface.
Roughness influence on human blood drop spreading and splashing
(70th Annual Meeting of the APS Division of Fluid Dynamics, Sunday–Tuesday, November 19–21, 2017; Denver, Colorado)

AGE DETERMINATION WITH METHYLATED DNA

DNA methylation is increasingly recognized for its potential use in age prediction. In this study, the author prediction model based on three CpG sites in three methylation markers was able to predict the age for liquid blood samples over 5 years.
Evaluation of DNA methylation-based age prediction on blood
(Forensic Science International Genetics, Oct 2017).

NON-BAYESIAN METHOD FOR MATHEMATICAL CALCULATION OF THE WEIGHT OF SCIENTIFIC EVIDENCE

American colleagues highlight the inconsistency in the use of Bayesian statistics in forensics and propose a new method.
Likelihood Ratio as Weight of Forensic Evidence: A Closer Look
(NIST publications)

PULP CAVITY OF A SUPERIOR CANINE TO ESTIMATE AGE

The authors propose an estimate of the age of individuals based on the ratio of pulp volume to dental volume from morphological data from 3D views of the upper canine pulp cavity.
Morphology and Volume of Maxillary Canine pulp cavity for individual Age estimation in Forensic Dentistry
(Int. J. Morphol., 35(3):1058-1062, 2017)

EFFECT OF ANTICOAGULANTS ON BLOOD

The authors show us that taking anticoagulants modifies the cohesion of the blood
Effect of anticoagulation therapy on drying times in bloodstain pattern analysis 
(International Journal of Legal Medicine, pp. 1-7, May 2017).
If we could expect this type of drug to affect the rheology and drying time of the blood, they do not change the shape of the expected traces.

KEY FOR IDENTIFYING BLOOD TRACE PATTERNS

In order to make the identification of blood trace models robust and objective, I have developed for several years a process for identifying blood trace models based solely on morphological criteria of the traces studied and the supports on which they are found.
Bloodstain Pattern Identification Key

BLUESTAR VS LUMISCENE ULTRA

The study compared Bluestar with Lumiscene Ultra. The authors conclude that the intensity of the reaction decreases more quickly with the Bluestar but that its luminescence and therefore observation time is longer.
Duration and intensity of chemiluminescence of different luminol kits,
(Rechtsmedezin, vol 27, pp. 1-6).

AUTOMATIC FINGERPRINT IDENTIFICATION

The evaluation conducted on behalf of the U.S. federal standards body indicates that the tools currently in use are not satisfactory. The interest of authorization makes the authors propose a new technique based on automatic learning (ConNets).
Automated latent fingerprint recognition

IDENTIFICATION AUTOMATIQUE DES EMPREINTES DIGITALES

L’évaluation menée au nom de l’organisme fédéral américain de normalisation fait état que les outils actuellement utilisés ne sont pas satisfaisants. L’intérêt de l’autorisation fait que les auteurs proposent une nouvelle technique basée sur l’apprentissage automatique (ConNets).
Automated latent fingerprint recognition

PHOTOGAMMETRY IN BLOODSTAIN PATTERN ANALYSIS

The authors discuss the advantages and disadvantages of using photogammetry routinely for bloodstain pattern analysis
The currently available possibilities for the application of photogrammetry in the forensic medical expertise of the blood stains at the scene of the crime,
(Sud Med Ekspert. 2017; 60(2) : pp. 41-44). My experience leads me to add that, to my knowledge, this is the best 3D modelling technique for the activity but that its use remains difficult on site. Article in Russian….

INTERPRETATION OF EJECTION MODELS

The study conducted by the authors corrects the common interpretation of the circular aspect of the traces composing an ejection model.
Interpretation von Schleuderspuren im Rahmen der Blutspurenmusteranalyse,
(Rechtsmedizin vol 27(2), pp. 83-97).

ESTIMATION OF THE DENTAL AGE OF ADULTS

The authors share with us their new method for detecting traces of weapons on the skin and clothing following a simple transport or storage.
The Journal of Eastern European Law 35, 2017

Forensic Science International, 2017

DETECTION OF WEAPON TRACES ON SKIN AND CLOTHING

The authors share with us their new method for detecting traces of weapons on the skin and clothing following a simple transport or storage.
The Journal of Eastern European Law 35, 2017

STUDY OF EJECTION MODELS

For those who can read German, I think this article is interesting. I proposed to its author to come and present his work at the European Morphoanalysis Conference in Poland, for which I am the scientific coordinator.
(Rechtsmedizin 2017, pp 1–5)

Here is a book that will provide an approach to the Baysian networks that are increasingly used in the argumentation of analytical results.
Designing and Understanding Forensic Bayesian Networks using Argumentation
dspace.library.uu.nl

DETERMINATION OF THE POST-MORTEM DELAY

The authors propose a method based on tryptophan contained in the vitreous humor to determine the postmortem delay. Their study gives interesting results. To be continued
Journal of Forensic Sciences, février 2017

BLOOD: MALE OR FEMALE?

Without waiting for the validation of their method, the authors reveal that RAMAN spectroscopy can be used to determine the type of dry blood traces. A portable RAMAN will then be able to determine in situ the identification of fluids with information such as race, gender, etc.
Analytical Chemistry, December 23, 2016

TRAJECTORY STUDY WITH A LASER SCANNER

The authors studied the accuracy of the FARO Focus3D laser scanner to determine the area of origin of projections following percussion. The results enter a tennis ball even if the deformation of the traces as a function of the curvature of the soiled surface cannot be determined
IABPA news, 32 (2):pp. 21-26

MRNA: IDENTIFICATION OF TRACES OF OLD BLOOD

The authors demonstrate the effectiveness of message RNA in identifying traces of old blood
Forensic Science International, 2017

DATING OF BLOOD TRACES

Authors recognized as eminent researchers in the field of blood trace dating show that today no method applicable in a crime scene exists.
chapitre : Blood degradation and bloodstain age Estimation

HUMAN BLOOD VS. FLUID DECOMPOSITION

This academic study provides us with a detailed review of the techniques used to differentiate human blood from decomposition fluids.
Master of Forensic Science de Rachel Lee Anderson

AREA OF ORIGIN DETERMINATION

This thesis studies the interest of taking the smallest projections (<3mm) to determine the 3D position of the blood source.
Master of Forensic Science de Brinda Salaskar.
This interesting work also shows the limits of this method on a real stage and therefore the relevance of my Limiting Angles method.

DETERMINATION OF BLOOD TRACE TRAJECTORIES AFTER A FIREARM SHOT

The authors develop a tool to simulate the dispersion of blood traces following a ballistic shooting. They find little difference between their reconstruction and their testing. However, using a 100ml plastic bag of blood for their tests, they conceal the potential action of bone and organic debris from a ballistic injury.
Indian Journal of Forensic Médecine & Toxicology, 2017 11(1): pp. 239-249

THE BLOOD ON THE CLOTHES

The authors, known for their involvement in the study of blood traces on tissues, confirm the significant influence of this type of support on traces of blood contaminating it. This is why interpretation based solely on traces of blood contaminating tissues remains difficult or even impossible today.
IABPA news 32(2): pp. 15-20

IMPACT OF A DROP ON A HARD SURFACE

The authors studied the behaviour of a drop of water on impact on a hard surface by varying the impact velocity and Weber number. This allows a better understanding of the blood trace found on the scenes studied.
55th AIAA Aerospace Sciences meeting, 2017

LUMICYANO KIT

This study shows that the new version of the Lumicyano, the Lumicyano Kit, gives better results on fresh or not, revealed on glass, aluminium and light or dark plastics.
Journal of Forensic Identification, 66 (6), pp. 560-576

3D LOCATION OF THE AREA OF ORIGIN

This thesis aims to demonstrate the effectiveness of small projections in determining the area of origin: 3D position of the blood source.
Thèse de Ryan Pugh

LUMICYANO KIT

Cette étude montre que la nouvelle version du Lumicyano, le Lumicyano Kit, donne de meilleurs résultats sur des empreintes fraiches ou non, révélées sur du verre, de l’aluminium et sur des plastiques clairs ou sombres.
Journal of Forensic Identification, 66 (6), pp. 560-576

FORENSIC USE OF GUNSHOT RESIDUE

This thesis explores the difficulties of using gunshot residue as forensic evidence
Thèse de Ashley Le

BLOOD DATING

The authors propose a smartphone application: Smart Forensic Phone to date blood thanks to its coloration linked to the presence of deoxygenated hemoglobin
Sensors and Actuators B: Chemical, 243, pp 221-225
But I didn’t find it on the Play Store of my phone, maybe in 2017.

SEX IDENTIFICATION OF SALIVA TRACES

The authors propose a RAMAN technique to identify the sex of the donor of saliva traces found. They obtain 92% success on traces found on the scene of facts.
Sex determination based on Raman spectroscopy of saliva traces for forensic purposes
(Analytical Chemistry novembre 2016).

BITE IDENTIFICATION

The authors offer us a review of the different techniques for identifying existing bites.
Forensic bitemark identification: weak foundations, exaggerated claims
 (Journal of Law and the Biosciences November 2016).

STUDY OF BLOOD TRACE TRAJECTORIES

The authors propose a study of the trajectories by performing calculations on the images of the initial findings after processing.
Conférence CASP, juin 2016

IDENTIFICATION OF BLOOD TRACES IN THE FUTURE

The authors propose a tool that could automate the identification of blood traces on stage. To be further developed…
7ème conférence chinoise à Chengdu 5-7 novembre 2016

NON-CONTACT IMPRESSION

The authors propose a method to improve the contrast of contactless prints and thus their exploitation.
ICIEA 2016 Conférence

RETURN OF THE TMB!

The Combur3 Test® E (Roche Diagnostics Corporation) is a presumptive test based on TMB to identify blood. The exploitation of this molecule began in forensics in the 1950s but still does not seem to discriminate against human blood.
Forensic Chemistry

GUN IN A FIRE

The authors provide us with the results of their work on the factors that influence the ability to make a link between fired ammunition and pistols recovered from a burned car Science & Justice, 2016

STATISTICAL EVALUATION OF DNA MIXTURES

The author provides us with a statistical evaluation of the identification of DNA mixtures through a real case study
Topics on Methodological and Applied Statistical Inference, Art of the series Studies in Theoretical and Applied Statistics pp 173-180

DEFORMED FINGERPRINTS

Fingerprints remain the simplest way to identify the presence of an individual at a fact scene. So the development of software by our Indian colleagues to exploit these fingerprints by automatic identification systems is important.
International Journal of Innovative technologies, Vol 4 (8), 2016, pp: 1504-1510

STATISTICS AND THE JURY

The communication of statistical results in court remains a challenge. The study of our colleagues gives us tools to improve this transmission.
Feel free to ask me for the full article.
Journal of Forensic Identification, 2016, Vol. 66 (5), pp. 405-425

DATING OF BLOOD TRACES

Many teams around the world are trying to find the right method to date blood traces. My research is in line with this Indian article where spectrometry seems to be the best way forward.
Feel free to ask me for the full article.
Indian Internet Journal of Forensic Medicine & Toxicology Vol. 13 (2), 2015, pp. 25-29 

SAMPLING TECHNIQUES FOR BLOODY FINGERPRINTS

Our American colleague compares two techniques often used for tool marks and bloody fingerprints. AccuTrans seems to give more information.
Feel free to ask me for the full article.
Journal of Forensic Identification, 2016, Vol. 66 (5), pp. 381-387

IDENTIFICATION OF BLOOD TRACE MODELS

For years I have been advocating for an objective and verifiable identification of blood trace patterns. Current work in New Zealand supports this method.
Forensic Science International 257 (2015) pp. 220-228
Science & Justice, 56 (2) (2016), pp. 123-128

SHOOTING RESIDUES

The authors present and critique the methods used for the interpretation of gunshot residue.
Forensic Science International, 2016

DNA RESEARCH & FINGERPRINTS

The authors’ work makes it possible to highlight methods that make it possible to discover both fingerprints and contact DNA.
International Journal of Forensic Medicine, 2016: pp. 1-9

REAR-PROJECTIONS

Although everyone is familiar with back-projection, few are familiar with the phenomenon. Then the theoretical model proposed by the authors could make it possible to better identify these traces in the diversity of projections that may be present at a crime scene.
American Physic Society Division of Fluid Mechanics Annual Meeting in Portland, Oregon, USA
Conférence le 21 novembre à 10:40

DENTAL AGE ESTIMATION METHOD

The article describes a promising and non-invasive method of estimating human age. This is the calculation of the pulp-tooth ratio of the central incisor of the jawbone for which, among the software used, AutoCAD and Adobe Photoshop are the most accurate.
S Basoya, VC Vinod, P Nath, AD Bhogte :
Estimation of Age by Pulp-Tooth Area ration using Three Computer aided software’s – Quality in Primary Care (2016) 24 (4): 161-166).

SUICIDE / HOMICIDE ?

Some murderers try to hide their actions by staging them in a way that makes them think of suicide. This article highlights the clues to identify a real suicide through psychological autopsy (1), suicidal reconstitution (2), crime scene analysis (3) and psychological clues (4).
J. Vandevoorde, N. Estano (La Revue de Médecine Légale)
Homicide maquillé et suicide : complémentarité de la suicidologie, de la criminologie et de la médecine légale

FROM SWAB TO PROFILE WITH FASTDNA

Through the demonstration of the advances of the MiDAS system, an interesting presentation of how the card used in the FastDNA system works.
Journal of Forensic Investigation, 2 (2), 2014

DNA VS. FINGERPRINT BRUSH

The fingerprint brush remains a vector of DNA contamination. And the powdered ones seem to be the most harmful according to the work of Hee Won Min & Sungwook Hong.
Analytical Science and Technology, 29 (2), 2016, pp.85-93

DNA VS. FINGERPRINT BRUSH

The fingerprint brush remains a vector of DNA contamination. And the powdered ones seem to be the most harmful according to the work of Hee Won Min & Sungwook Hong.
Analytical Science and Technology, 29 (2), 2016, pp.85-93

DNA ON THE JEAN

Permanganate/chelex is able to eliminate PCR inhibitors on various garments including Jean (denim).
International Journal of Legal Medicine, pp 1-9

DNA ON FINGERPRINT

Method for improving the obtaining of a genetic profile on a fingerprint.
Science & Justice, sept 2016

DNA MIXTURE

The publication “Evaluation of forensic DNA mixture evidence: protocol for evaluation, interpretation, and statistical calculations using the combined probability of inclusion” presents a working protocol for DNA mixtures for which the validation of the expert’s interpretation may be problematic..
BMC Genetics 2016, 17:125

DNA PROFILE AFTER CLEANING

THANK YOU to Erin Houston for her work and thesis “The effects of various laundering factors on the recoverability of DNA” published by Wright State University (Ohio – USA).  It demonstrates that DNA can be found with standard extraction techniques after the use of cleaning products or machine cleaning (Chapters 2, 3) and that DNA transfers into the machine are possible (Chapter 4).
Thèse

INTERPRETATION OF BLOOD ALCOHOL LEVEL

In cases that fortunately remain rare, the interpretation of blood alcohol levels can be problematic.
JFLM44

FASTDNA

The FastDNA technique allows a genetic profile to be obtained in one hour. This validation conducted in the United States by Angelo Della Manna’s team and soon published in the FSI Genetics, shows the seriousness of the technique.
FSIGEN 1578