Forensic investigative genetic genealogy: expanding pedigree tracing and genetic inquiry in the genomic era.

Genetic genealogy provides crucial insights into the complex biological relationships within contemporary and ancient human populations by analyzing shared alleles and chromosomal segments that are identical by descent, to understand kinship, migration patterns, and population dynamics. Within forensic science, forensic investigative genetic genealogy (FIGG) has gained prominence by leveraging next-generation sequencing technologies and population-specific genomic resources, opening new investigative avenues. In this review, we synthesize current knowledge, underscore recent advancements, and discuss the growing role of FIGG in forensic genomics. FIGG has been pivotal in revitalizing dormant inquiries and offering new genetic leads in numerous cold cases. Its effectiveness relies on the extensive SNP profiles contributed by individuals from diverse populations to specialized genomic databases. Advances in computational genomics and the growth of human genomic databases have spurred a profound shift in the application of genetic genealogy across forensics, anthropology, and ancient DNA studies. As the field progresses, FIGG is evolving from a nascent practice into a more sophisticated and specialized discipline, shaping the future of forensic investigations.

Review of the lethal mechanism of insulin poisoning and the characteristic of forensic identification.

Insulin, as the only hypoglycemic hormone in the body, plays a key role in blood sugar control. However, excessive insulin intake can lead to insulin poisoning and even death, which often occurs in clinical and forensic work. At present, some researches on insulin poisoning have been carried out at home and abroad, however, it seems that the mechanism and forensic characteristics of insulin poisoning are not clear and complete. Therefore, in this paper, we reviewed the potential mechanism of insulin poisoning, the methods of insulin detection and the forensic identification of poisoning cases, aiming at providing services for the forensic identification of insulin poisoning.

Forensic age estimation of adolescents using computed tomography of the clavicles.

In forensic age estimation, CT imaging of the clavicles is used to determine an age over completed 21 years. If ossification of the medial clavicular epiphysis is complete, young men are assumed to be over 21 years of age. The aim of this study is to check the statistical parameters (specificity, predictive probability) for the characteristic "completed ossification of the medial clavicles". 285 male patients who, for various reasons, received a chest CT at the Medical Center of the University of Freiburg between 1st December 2019 and 6th December 2022 were screened for the study, of whom 203 patients were included in the study. The stage of clavicular ossification was classified as stage 1 - 5 according to Schmeling. While 70 out of 71 patients under 21 years of age were correctly estimated to be under 21 years of age, there was one patient whose ossification on one side was classified as stage 4 and who would therefore have been estimated to be over 21 years of age. If only subjects whose ossification stage was the same on both sides are included, the specificity of the test method is 100% and the positive predictive probability is 100%. If patients for whom only one side is stage 4 are also included, the specificity is 98.6%. Thus, only the complete and symmetrical ossification of both clavicles (stage 4 according to the Schmeling classification) in a standardised thin-layer CT can be classified as a reliable indicator of an age over 21 years in young men. In the case of asymmetric ossification of the medial clavicles (stage 4 is not reached on one side), false positive evaluations and the incorrect assumption of an age over 21 years can occur.

Forensic age estimation by MRI of the knee - comparison of two classifications for ossification stages in a German population.

AIM AND OBJECTIVES: In forensic age estimation e.g. for judicial proceedings surpassed age thresholds can be legally relevant. To examine age related differences in skeletal development the recommendations by the Study Group on Forensic Age Diagnostics (AGFAD) are based on ionizing radiation (among others orthopantomograms, plain x-rays of the hand). Vieth et al. and Ottow et al. proposed MRI-classifications for the epiphyseal-diaphyseal fusion of the knee joint to define different age groups in healthy volunteers. The aim of the present study was to directly compare these two classifications in a large German patient population. MATERIALS AND METHODS: MRI of the knee joint of 900 patients (405 female, 495 male) from 10 to 28 years of age were retrospectively analyzed. Acquired T1-weighted turbo spin-echo sequence (TSE) and T2-weighted sequence with fat suppression by turbo inversion recovery magnitude (TIRM) were analyzed for the two classifications. The different bony fusion stages of the two classifications were determined and the corresponding chronological ages assigned. Differences between the sexes were analyzed. Intra- and inter-observer agreements were determined using Cohen's kappa. RESULTS: With the classification of Ottow et al. it was possible to determine completion of the 18th and 21st year of life in both sexes. With the classification of Vieth et al. completion of the 18th year of life for female patients and the 14th and 21st year of life in both sexes could be determined. The intra- and inter-observer agreement levels were very good (κ > 0.82). CONCLUSION: In the large German patient cohort of this study it was possible to determine the 18th year of life with for both sexes with the classification of Ottow et al. and for female patients with the classification of Vieth et al. It was also possible to determine the 21st year of life for all bones with the classification of Ottow et al. and for the distal femur with the classification of Vieth et al.

Cardiac rhabdomyoma: an uncommon culprit in sudden infant death.

Sudden death in infants remains a common and poorly understood cause of childhood mortality in the USA. Pediatric cardiac tumors, although rare, may underlie some cases of unexplained sudden infant death. Autopsy is a crucial diagnostic step in these cases, as both gross and microscopic examination of the heart may uncover occult cardiac tumors. Rhabdomyomas are the most common cardiac tumors in childhood and may result in arrythmia and sudden death. We present a case of sudden death in a healthy 5-month-old infant which initially appeared "SIDS-like" until thorough histological analysis revealed an underlying cardiac rhabdomyoma. The case is of particular importance in that the gross examination of the heart was considered completely normal, and the tumor only involved certain portions of the heart microscopically. Had a single random section of myocardium been the only heart section examined microscopically, the diagnosis might have been missed. This case emphasizes the importance of thorough microscopic examination in infant cases, especially in cases where the heart appears grossly normal.

A retrospective study of 29 fatal cases of insulin overdose.

PURPOSE: To summarize recent cases of fatal insulin poisoning both domestically and internationally, thereby offering valuable insights for the forensic identification of insulin overdose cases. METHODS: Literature published since 2000 on fatal insulin overdose were systematically searched and screened. Data encompassing variables such as year, age, sex, cause of death, scene conditions, occupations, medical histories of victims and perpetrators, autopsy timing, dosage and administration methods, forensic pathology, and toxicological analysis, were compiled for rigorous statistical analysis. RESULTS: Among the 29 fatal cases of insulin poisoning, suicides and homicides accounted for 55.2 % and 41.4 %, respectively. Precisely 34.5 % of victims or perpetrators were associated with the medical industry, 27.6 % had diabetes, and 24.1 % had mental illnesses such as depression. Intravenous injection resulted in quicker death than did subcutaneous injection. In some cases, immunohistochemical staining of insulin and protamine at injection sites yielded positive results. The average molar ratio of insulin to C-peptide in post-mortem blood was 13.76 ± 5.167, indicating a significant diagnostic value for insulin poisoning. CONCLUSION: Assessment of cases of fatal insulin overdose should be thorough, incorporating case investigation, scene examination, medical records review, autopsy findings, pathological examinations, and laboratory tests, alongside considering the condition of the body and timing of death autopsy. Using mass spectrometry to detect insulin proves valuable, particularly in cases of poor body preservation.

Identification of N-piperidinyl etonitazene in alternative keratinous matrices from a decomposing cadaver.

This short report describes research on N-piperidinyl etonitazene, also known as etonitazepipne, in keratinous matrices (hair and nails) after death related to a suspected opioid overdose. Etonitazepipne belongs to the family of benzimidazole opioids, a class of new synthetic opioids that has penetrated the illicit drug market. Analysis in the case under study showed the presence of etonitazepipne in both hair and nails, confirming that the substance accumulates in the body with repeated intake.

The analysis of methylamphetamine and para-hydroxy-methylamphetamine in post-mortem hair samples using liquid chromatography-tandem mass spectrometry.

External contamination is a well-recognized limitation of hair analysis for drugs of abuse like methylamphetamine (MA), and there are no guidelines regarding the analysis of specific metabolites of MA to assist interpretation. We developed an analytical method to detect MA, amphetamine (AMP), and para-hydroxy-methylamphetamine (p-OH-MA) in hair and present their concentrations among a cohort of deceased persons positive for MA in blood (n = 63). Hair samples (≤ 3 cm) were washed with dichloromethane and water prior to extraction using a methanolic micro-pulverization. The reconstituted hair extracts were separated on a UCT Selectra® Aqueous C18 HPLC Column (100 × 2.1 mm, 3 µm) by gradient elution and detected using a Sciex Triple Quad 6500+ system. Validation was satisfactory, and the lower limits of quantitation were 0.01 ng/mg for MA and AMP and 0.001 ng/mg for p-OH-MA. The median hair concentrations of MA, AMP, and p-OH-MA were 13 ng/mg (range = 0.015-49; n = 51), 1.1 ng/mg (range = 0.018-44; n = 60), and 0.020 ng/mg (range = 0.0012-0.38, n = 62), respectively. These concentrations in hair were strongly positively correlated (r = .7202 to .8641, p < .001), suggesting similar modes of incorporation. Moreover, the wash/hair ratios were indicative of external contamination, especially among the soiled group of hair samples. Therefore, further studies are necessary to determine concentrations of p-OH-MA in living MA users and confirm if this metabolite constitutes a potential marker of MA consumption.

A medico-legal perspective on postictal violence: A case study and systematic review of postictal delirium.

Detailed descriptions of violent postictal episodes are rare. We provide evidence from an index case and from a systematic review of violent postictal episodes that demonstrates the encephalopathic features of some violent postictal behaviors. We discuss how these cases may fit in the legal framework of culpability. The data support the view that some episodes of violent postictal behavior are more accurately classified as a neurological delirium or encephalopathy rather than as a postictal psychosis. Current medical terminology may present unwarranted (and presumably unintended) barriers to exculpation for patients who exhibit post-ictal violence during an episode of delirium during which the patient was unaware of his or her violent conduct.

Analysis of the privacy-performance tradeoff of reference testing in Forensic Investigative Genetic Genealogy.

During an investigation using Forensic Investigative Genetic Genealogy, which is a novel approach for solving violent crimes and identifying human remains, reference testing-when law enforcement requests a DNA sample from a person in a partially constructed family tree-is sometimes used when an investigation has stalled. Because the people considered for a reference test have not opted in to allow law enforcement to use their DNA profile in this way, reference testing is viewed by many as an invasion of privacy and by some as unethical. We generalize an existing mathematical optimization model of the genealogy process by incorporating the option of reference testing. Using simulated versions of 17 DNA Doe Project cases, we find that reference testing can solve cases more quickly (although many reference tests are required to substantially hasten the investigative process), but only rarely (<1%) solves cases that cannot otherwise be solved. Through a mixture of mathematical and computational analysis, we find that the most desirable people to test are at the bottom of a path descending from an ancestral couple that is most likely to be related to the target. We also characterize the rare cases where reference testing is necessary for solving the case: when there is only one descending path from an ancestral couple, which precludes the possibility of identifying an intersection (e.g., marriage) between two descendants of two different ancestral couples.

Single-camera photogrammetry using a mobile phone for low-cost documentation of corpses.

Photogrammetry is a technique for studying and defining objects' shape, dimension, and position in a three-dimensional space using measurements obtained from two-dimensional photographs. It has gained popularity following the development of computer graphics technologies and has been applied to various branches of medicine. In this study, the authors present a method for low-cost photorealistic documentation of corpses during autopsy using single-camera photogrammetry with a mobile phone. Besides representing the body by demonstrating the injured and non-injured body parts as control, evidencing the body parts on a 3D reconstruction allows easy explanation to nonmedical experts such as lawyers.

Heart proteomic profiling discovers MYH6 and COX5B as biomarkers for sudden unexplained death.

Sudden unexplained death (SUD) is not uncommon in forensic pathology. Yet, diagnosis of SUD remains challenging due to lack of specific biomarkers. This study aimed to screen differentially expressed proteins (DEPs) and validate their usefulness as diagnostic biomarkers for SUD cases. We designed a three-phase investigation, where in the discovery phase, formalin-fixed paraffin-embedded (FFPE) heart specimens were screened through label-free proteomic analysis of cases dying from SUD, mechanical injury and carbon monoxide (CO) intoxication. A total of 26 proteins were identified to be DEPs for the SUD cases after rigorous criterion. Bioinformatics and Adaboost-recursive feature elimination (RFE) analysis further revealed that three of the 26 proteins (MYH6, COX5B and TNNT2) were potential discriminative biomarkers. In the training phase, MYH6 and COX5B were verified to be true DEPs in cardiac tissues from 29 independent SUD cases as compared with a serial of control cases (n = 42). Receiver operating characteristic (ROC) analysis illustrated that combination of MYH6 and COX5B achieved optimal diagnostic sensitivity (89.7 %) and specificity (84.4 %), with area under the curve (AUC) being 0.91. A diagnostic software based on the logistic regression formula derived from the training phase was then constructed. In the validation phase, the diagnostic software was applied to eight authentic SUD cases, seven (87.5 %) of which were accurately recognized. Our study provides a valid strategy towards practical diagnosis of SUD by integrating cardiac MYH6 and COX5B as dual diagnostic biomarkers.

Influence of photoperiod on the developmental times of the forensically relevant blow fly species Calliphora vicina (Diptera: Calliphoridae).

Blow flies (Diptera: Calliphoridae) are frequently used in forensic investigations due to their rapid colonization of cadavers. As with other insects, environmental temperature strongly influences their developmental rates. While published research has typically explored not only the impact of the environmental temperature, but also of other factors like tissue type and drug presence on developmental rates, the influence of photoperiod on the developmental rates of forensically relevant blow fly species has remained largely underexplored. Understanding the relationship between photoperiod and developmental times is crucial, as neglecting this aspect could compromise the accuracy of minimum post-mortem interval (minPMI) estimations. The present study investigates the impact of three photoperiod conditions (0:24, 8:16, and 12:12 light:darkness) on the developmental rates of Calliphora vicina, focusing on the duration of the different immature stages and on the total developmental time. Our results revealed significant variation in the intra-puparial stage and total development time across different photoperiods. Notably, a 12:12 photoperiod led to a significantly prolonged intra-puparial stage and total development time compared to the 0:24 photoperiod, suggesting that Calliphora vicina develops faster in total darkness. These findings highlight the importance of considering photoperiod in both laboratory rearing protocols and forensic casework to improve the accuracy and reliability of minPMI estimations. In this regard, preliminary guidelines and recommendations are provided.

Changes in the microbial community of semen exposed to different simulated forensic situations.

Semen is one of the common body fluids in sexual crime cases. The current methods of semen identification have certain limitations, so it is necessary to search for other methods. In addition, there are few reports of microbiome changes in body fluids under simulated crime scenes. It is essential to further reveal the changes in semen microbiomes after exposure to various simulated crime scenes. Semen samples from eight volunteers were exposed in closed plastic bags, soil, indoor, cotton, polyester, and wool fabrics. A total of 68 samples (before and after exposure) were collected, detected by 16S rDNA sequencing, and analyzed for the microbiome signature. Finally, a random forest model was constructed for body fluid identification. After exposure, the relative abundance of Pseudomonas and Rhodococcus changed dramatically in almost all groups. In addition, the treatment with the closed plastic bags or soil groups had a greater impact on the semen microbiome. According to the Shannon indices, the alpha diversity of the closed plastic bags and soil groups was much lower than that of the other groups. Attention should be given to the above two scenes in practical work of forensic medicine. In this study, the accuracy of semen recognition was 100%. The exposed semen can still be correctly identified as semen based on its microbiota characteristics. In summary, semen microbiomes exposed to simulated crime scenes still have good application potential for body fluid identification. IMPORTANCE: In this study, the microbiome changes of semen exposed to different environments were observed, and the exposed semen microbiome still has a good application potential in body fluid identification.

Putting the usability of wearable technology in forensic psychiatry to the test: a randomized crossover trial.

Introduction: Forensic psychiatric patients receive treatment to address their violent and aggressive behavior with the aim of facilitating their safe reintegration into society. On average, these treatments are effective, but the magnitude of effect sizes tends to be small, even when considering more recent advancements in digital mental health innovations. Recent research indicates that wearable technology has positive effects on the physical and mental health of the general population, and may thus also be of use in forensic psychiatry, both for patients and staff members. Several applications and use cases of wearable technology hold promise, particularly for patients with mild intellectual disability or borderline intellectual functioning, as these devices are thought to be user-friendly and provide continuous daily feedback. Method: In the current randomized crossover trial, we addressed several limitations from previous research and compared the (continuous) usability and acceptance of four selected wearable devices. Each device was worn for one week by staff members and patients, amounting to a total of four weeks. Two of the devices were general purpose fitness trackers, while the other two devices used custom made applications designed for bio-cueing and for providing insights into physiological reactivity to daily stressors and events. Results: Our findings indicated significant differences in usability, acceptance and continuous use between devices. The highest usability scores were obtained for the two fitness trackers (Fitbit and Garmin) compared to the two devices employing custom made applications (Sense-IT and E4 dashboard). The results showed similar outcomes for patients and staff members. Discussion: None of the devices obtained usability scores that would justify recommendation for future use considering international standards; a finding that raises concerns about the adaptation and uptake of wearable technology in the context of forensic psychiatry. We suggest that improvements in gamification and motivational aspects of wearable technology might be helpful to tackle several challenges related to wearable technology.

Rethinking scientific communication in courts: A question of credibility.

The high value placed on forensic information in the criminal justice process is demonstrated by the fallout resulting when questions are raised as to the validity of methods used, deficiencies in the understanding of the limitations of results, or uncertainties around the professional expertise or ethical practices of the provider of the information. To effectively act as the "speaker" for the scientific evidence in court, forensic science needs to have credibility. The workshop "Rethinking scientific communication in courts" held at the Australian National University College of Law in November 2023 explored the subject of science communication in the legal context through the lens of philosophy, law, forensic service provision and meta-science, demonstrating the unique challenges placed on the field of forensic science as a scientific profession confined and defined within a non-scientific system. Stemming from the discussions at the workshop, this paper examines the notion of credibility in science, how forensic science aligns with the hallmarks of a credible scientific community and the influence this has on our understandings of scientific communication in courts.

A Three-Year Investigation on Corpses Referred to Legal Medicine Organization from An Iranian General Hospital: A Cross-Sectional Study.

Background: A Medical Certificate of Cause of Death (MCCD) is a legal and enforceable document issued by the attending physician. However, according to the instructions, in many cases such as sudden, unexplained, and extraordinary deaths, along with some uncommon causes, such as cases suspicious of murder, the deceased patient must be referred to the Iranian Legal Medicine Organization (ILMO). Moreover, the unnecessary referral of corpses to ILMO can increase the workload of the staff, finally confronting the family of the deceased with high emotional and financial costs. Methods: In this cross-sectional study, the medical records of all deceased patients referred from Hazrat Rasool Hospital to the ILMO (565 cases) in a three-year period from April 2016 to March 2019 were investigated and analyzed using SPSS22 software with chi-squared and T-test. Results: Among all the patients who passed away during this time (4,239 patients), 565 were referred to ILMO, accounting for 13.3% of deaths. The most common causes of referral were car and motorcycle accidents, with a total prevalence of 27.1%, dead-on-arrival (DOA) prevalence of 21.3%, and death with an unknown cause prevalence of 15.3%. Significant correlation was also detected between causes of referral with gender, time of death, and age. For example, Car accidents and lawsuits against medical staff were more common in men and women, respectively. Conclusion: Car and motorcycle accidents, DOA, and unknown causes were the most prevalent causes of referral in this study. In general, few studies have been conducted regarding the causes of referral of the deceased to the Legal Medicine Organization. In this study, we collected relevant variables to investigate this issue thoroughly.

Forensic Assessment of Alcohol Intoxication in Cases of Fatal Road Traffic Accidents in Lithuania.

Background: There is strong evidence that alcohol consumption is a significant risk factor for fatal road traffic accidents. It is estimated that the number of alcohol-related road accidents remains high in the past few years in Lithuania. This study aims to examine the prevalence of alcohol in blood samples collected from the autopsy results of road traffic accident victims. Materials and methods: A retrospective study of 136 road traffic accident victims was performed in State Forensic Medicine Service of Lithuania in the period of 2013 to 2023. We analyzed blood alcohol concentration (BAC) in relation to sex, age, road user type, place and time of the day at death. Results: 31% of the victims were under influence of alcohol at the time of death, with mean BAC 1.99 ± 0.92‰. The mean BAC was 2.16 ± 0.8‰ in male and 1.18 ± 1.12‰ in female group. By the type of road users, 23% of the pedestrians (mean BAC 2.45 ± 0.71‰), 32% of car drivers (mean BAC 2.13 ± 0.75‰), 41% of vehicle passengers (mean BAC of 1.73 ± 1.19‰), 37% of the motorcycle riders (mean BAC of 1.28 ± 0.53‰), 37% of the cyclists (mean BAC of 1.15 ± 0.75‰) were found to be intoxicated during the time of accident. Highest mean blood alcohol concentration was found during the night time hours (9 p. m. - 5 a. m.) 2.28 ± 0.91, comparing to in afternoon hours (12 p. m. - 5 p. m.) 1.49 ± 0.99, evening hours (5 p. m. - 9 p. m.) 2.10 ± 0.73 and morning hours (5 a. m. - 12 p. m.) 1.94 ± 1.00. The mean BAC in road traffic accidents during summer was 1.48 ± 0.71‰, spring 2.25 ± 0.76‰, autumn 2.12 ± 1‰, winter 2.42 ± 1‰. Conclusions: Alcohol consumption by road users is a significant contributing factor in road traffic accidents and their outcomes in Lithuania.

Deaths during Sexual Activity.

Background: Deaths during sexual activities are rarely identified phenomena in forensic medicine practice. Most often, such deaths are classified as accidents or deaths due to the manifestation of certain diseases during sexual activity. It is important to rule out homicide or suicide as the cause of death when investigating sexual deaths. Determining the cause of death requires a comprehensive assessment of the evidence and circumstances and should not be based solely on autopsy findings. When determining the cause of death, it is necessary to evaluate the circumstances of the discovery, important evidence found near the body, the position of the deceased, the place where the deceased was found, and the characteristics of the environment. Cases: Case 1: A 65-year-old male was clothed in women's underwear and was found hanging in a noose in a bedroom after a house fire. The autopsy revealed a ligature mark on the neck, bruises in neck muscles, tears in carotid arteries, and signs of acute pulmonary distension. The cause of death was determined to be suffocation due to neck compression by a ligature, compounded by significant alcohol intoxication, with additional postmortem burns covering 30% of the body surface area likely occurring after death.Case 2: A 55-year-old naked male was found without external injuries but with a plastic tube inserted into the rectum, causing a 2.5 cm rupture in the ileum. The perforation led to complications, including purulent diffuse peritonitis, intoxication, and acute cardiac and respiratory failure, resulting in death within 3-6 hours after insertion. Concurrent findings included atherosclerotic changes in the heart, internal organ hyperemia and edema, hepatic steatosis, renal cyst, and a lack of ethyl alcohol in blood but 0.17 ‰ presence in urine according to toxicology analysis. Conclusions: A detailed evaluation of all the evidence is very important in the forensic examination of the deceased during sexual activity. Therefore, to determine the cause of death, not only the autopsy data, toxicological and microscopic examinations of the deceased are important, but also the evaluation of all findings at the scene. The most common cause of death of an autoerotic nature is asphyxia, and the most commonly identified group of the dead are men aged around 40 years.