scholarly journals Individualised and non-contact post-mortem interval determination of human bodies using visible and thermal 3D imaging

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Leah S. Wilk ◽  
Gerda J. Edelman ◽  
Martin Roos ◽  
Mara Clerkx ◽  
Inge Dijkman ◽  
...  

AbstractDetermining the time since death, i.e., post-mortem interval (PMI), often plays a key role in forensic investigations. The current standard PMI-estimation method empirically correlates rectal temperatures and PMIs, frequently necessitating subjective correction factors. To overcome this, we previously developed a thermodynamic finite-difference (TFD) algorithm, providing a rigorous method to simulate post-mortem temperatures of bodies assuming a straight posture. However, in forensic practice, bodies are often found in non-straight postures, potentially limiting applicability of this algorithm in these cases. Here, we develop an individualised approach, enabling PMI reconstruction for bodies in arbitrary postures, by combining photogrammetry and TFD modelling. Utilising thermal photogrammetry, this approach also represents the first non-contact method for PMI reconstruction. The performed lab and crime scene validations reveal PMI reconstruction accuracies of 0.26 h ± 1.38 h for true PMIs between 2 h and 35 h and total procedural durations of ~15 min. Together, these findings broaden the potential applicability of TFD-based PMI reconstruction.

Diagnostics ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1014
Author(s):  
Angela Zissler ◽  
Walter Stoiber ◽  
Peter Steinbacher ◽  
Janine Geissenberger ◽  
Fabio C. Monticelli ◽  
...  

Objectives: We provide a systematic review of the literature to evaluate the current research status of protein degradation-based postmortem interval (PMI) estimation. Special attention is paid to the applicability of the proposed approaches/methods in forensic routine practice. Method: A systematic review of the literature on protein degradation in tissues and organs of animals and humans was conducted. Therefore, we searched the scientific databases Pubmed and Ovid for publications until December 2019. Additional searches were performed in Google Scholar and the reference lists of eligible articles. Results: A total of 36 studies were included. This enabled us to consider the degradation pattern of over 130 proteins from 11 different tissues, studied with different methods including well-established and modern approaches. Although comparison between studies is complicated by the heterogeneity of study designs, tissue types, methods, proteins and outcome measurement, there is clear evidence for a high explanatory power of protein degradation analysis in forensic PMI analysis. Conclusions: Although only few approaches have yet exceeded a basic research level, the current research status provides strong evidence in favor of the applicability of a protein degradation-based PMI estimation method in routine forensic practice. Further targeted research effort towards specific aims (also addressing influencing factors and exclusion criteria), especially in human tissue will be required to obtain a robust, reliable laboratory protocol, and collect sufficient data to develop accurate multifactorial mathematical decomposition models.


2020 ◽  
Vol 21 (10) ◽  
pp. 3540 ◽  
Author(s):  
Pamela Tozzo ◽  
Salvatore Scrivano ◽  
Matteo Sanavio ◽  
Luciana Caenazzo

The determination of the post-mortal interval (PMI) is an extremely discussed topic in the literature and of deep forensic interest, for which various types of methods have been proposed. The aim of the manuscript is to provide a review of the studies on the post-mortem DNA degradation used for estimating PMI. This review has been performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and the PRISMA Guidelines. Several analytical techniques have been proposed to analyse the post-mortem DNA degradation in order to use it to estimate the PMI. Studies focused mainly on animal models and on particular tissues. The results have been mixed: while on the one hand literature data in this field have confirmed that in the post-mortem several degradation processes involve nucleic acids, on the other hand some fundamental aspects are still little explored: the influence of ante and post-mortem factors on DNA degradation, the feasibility and applicability of a multiparametric mathematical model that takes into account DNA degradation and the definition of one or more target organs in order to standardize the results on human cases under standard conditions.


2021 ◽  
Vol 9 (1-2) ◽  
pp. 49-58
Author(s):  
Md Golam Mostafa ◽  
Mst Shahanaz Parvin Shobha ◽  
Anjuman Ara ◽  
Saadia Ahmad

The post-mortem interval (PMI) of a jungle cat (Felis chaus) and a chicken (Gallus gallus domesticus) were estimated as a mammalian and an avian model, respectively. The estimations were performed adopting the Accumulated Degree Hours (ADH) method using blowfly, Lucilia sericata. The required developmental time from oviposition to the 3rd instar larvae of the blowfly species was considered for the determination of PMI in each of the study. The results revealed that the calculated PMI of jungle cat was 5.29 days. On the other hand, the estimated PMI of the chicken was 2.83 days. The difference of these two PMIs in two different models might be due to the variation of temperatures and other related factors in the development of the larvae of the blowfly species. This study might offer a new approach in the medico-legal investigations with a view to resolving homicide as well as other suspected death of animals including wildlife in Bangladesh. Jahangirnagar University J. Biol. Sci. 9(1 & 2): 49-58, 2020 (June & December)


2017 ◽  
Vol 295 ◽  
pp. 56-63
Author(s):  
Joanna Stojak ◽  

Entomotoxicology allows the estimation of the post-mortem interval and the determination of the cause of death in cases in which the corpse has decomposed and the tissues necessary for toxicological analysis are no longer available. Obtaining information about toxic substances potentially present in the body is possible by isolation of larvae and pupae of true flies (Diptera) and/or adult forms of, e.g., beetles (Coleoptera) present on or near the corpse. This article was intended to summarize the current knowledge in the field of entomotoxicology, including examples from the literature, and to present the impact of selected toxic substances and medicines on the development of necrophagous larvae of insects.


Insects ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 314
Author(s):  
Szymon Matuszewski

During death investigations insects are used mostly to estimate the post-mortem interval (PMI). These estimates are only as good as they are close to the true PMI. Therefore, the major challenge for forensic entomology is to reduce the estimation inaccuracy. Here, I review literature in this field to identify research areas that may contribute to the increase in the accuracy of PMI estimation. I conclude that research on the development and succession of carrion insects, thermogenesis in aggregations of their larvae and error rates of the PMI estimation protocols should be prioritized. Challenges of educational and promotional nature are discussed as well, particularly in relation to the collection of insect evidence.


Author(s):  
Idha Arfianti Wiraagni ◽  
Yudha Nurhantari ◽  
Siti Rahmah Umniyati

Flies are one type of insect, which decompose the organic component in animals, and human cadavers. Therefore, the insects can be used to help the investigators related to human law. One of the methods to determine Post Mortem Interval [PMI] was by identifying the insects that come in the decay process. Some chemicals can affect the development of the insect and its life cycle. Cyanide is widely used to commit murder in Indonesia. The effect of cyanide on the development and life cycle of insects is a very interesting field to study. The purpose of this study was to determine the effect of cyanide exposure to larvae weight for PMI estimation. This research was an experimental research that used larvae of Wistar rat carcass. The control group was killed by neck dislocation, while experimental group were killed by oral lethal doses of cyanide. Data were obtained from the measurement and examination of larvae, started from the 1st day until 4<sup>th</sup> day after death. Chrysomya, Sarcophaga, and Lucilia larvae were identified from this study. Sarcophaga larvae first appeared and next day followed by Chrysomya and Lucilia. There were significant differences in Chrysomya larvae weight. There were Chrysomya third instar larvae on the 4<sup>th</sup> day on cyanide group, with 56.4±16.8 mg of weight. There were Chrysomya third instar larvae on the 4<sup>th</sup> day on control group, with 30.4±5.5 mg of weight. The differences of larvae’s weight, among Sarcophaga and Lucilia larvae, could not be determined because there were not enough samples. Chrysomya third instar larvae of cyanide group significantly heavier than control group on 4<sup>th</sup> day. The differences of larvae weight, among Sarcophaga and Lucilia larvae, could not be determined because there were not enough samples.


2020 ◽  
Vol 135 (1) ◽  
pp. 223-233
Author(s):  
Ann-Sofie Ceciliason ◽  
M. Gunnar Andersson ◽  
Emma Lundin ◽  
Håkan Sandler

AbstractThe objective of this study was to determine if a relationship between microbial neoformation of volatiles and the post-mortem interval (PMI) exists, and if the volatiles could be used as a tool to improve the precision of PMI estimation in decomposed human remains found in an indoor setting. Chromatograms from alcohol analysis (femoral vein blood) of 412 cases were retrospectively assessed for the presence of ethanol, N-propanol, 1-butanol, and acetaldehyde. The most common finding was acetaldehyde (83% of the cases), followed by ethanol (37%), N-propanol (21%), and 1-butanol (4%). A direct link between the volatiles and the PMI or the degree of decomposition was not observed. However, the decomposition had progressed faster in cases with microbial neoformation than in cases without signs of neoformation. Microbial neoformation may therefore act as an indicator of the decomposition rate within the early decomposition to bloating stages. This may be used in PMI estimation based on the total body score (TBS) and accumulated degree days (ADD) model, to potentially improve the model’s precision.


2020 ◽  
Vol 135 (1) ◽  
pp. 253-267
Author(s):  
Ann-Sofie Ceciliason ◽  
M. Gunnar Andersson ◽  
Sofia Nyberg ◽  
Håkan Sandler

AbstractThe objective of this study was to determine if a novel scoring-based model for histological quantification of decomposed human livers could improve the precision of post-mortem interval (PMI) estimation for bodies from an indoor setting. The hepatic decomposition score (HDS) system created consists of five liver scores (HDS markers): cell nuclei and cell structure of hepatocytes, bile ducts, portal triad, and architecture. A total of 236 forensic autopsy cases were divided into a training dataset (n = 158) and a validation dataset (n = 78). All cases were also scored using the total body score (TBS) method. We specified a stochastic relationship between the log-transformed accumulated degree-days (log10ADD) and the taphonomic findings, using a multivariate regression model to compute the likelihood function. Three models were applied, based on (i) five HDS markers, (ii) three partial body scores (head, trunk, limbs), or (iii) a combination of the two. The predicted log10ADD was compared with the true log10ADD for each case. The fitted models performed equally well in the training dataset and the validation dataset. The model comprising both scoring methods had somewhat better precision than either method separately. Our results indicated that the HDS system was statistically robust. Combining the HDS markers with the partial body scores resulted in a better representation of the decomposition process and might improve PMI estimation of decomposed human remains.


Author(s):  
Mauro T Ave ◽  
Lucía Ordóñez-Mayán ◽  
Mercedes Camiña ◽  
Manuel Febrero-Bande ◽  
José Ignacio Muñoz-Barús

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