Journal of forensic sciences最新文献

In the case of a young woman's death by falling from the window of her boyfriend's sixth-floor apartment, investigators needed to determine whether the fall was suicidal or if the victim was forcibly pushed. The incident occurred at night, with her boyfriend being the only witness to how the fall happened. Establishing the origin of the material traces found on the woman's stockings and shoes, along with other clues, played a crucial role in resolving this dilemma. The traces found on the stockings and samples collected from the building's external wall were analyzed using digital stereomicroscopy, High-resolution scanning electron microscopy (HRSEM) coupled with energy dispersive X-ray spectroscopy (EDX), and optical microscopy. Chlorophyll presence on both the victim's stockings and the surface of the building façade was confirmed using Raman spectroscopy. The inorganic traces found on the shoes and the external wall were examined using stereomicroscopy and HRSEM coupled with EDX and were found to be similar in texture and elemental composition. The correspondence between the biological structures and mineral fragments, along with the dynamic friction marks found on the woman's body and shoes, confirmed physical contact between the victim and the external wall. These findings led to the conclusion that the victim struggled for her life and the fall resulted from a criminal act.

Microbial communities associated with the human body are highly dynamic and reflect the host environment and lifestyle over time. Studies show death is no exception, with data demonstrating similar antemortem and postmortem microbiomes up to 48 h following death. These predictable microbial biomarkers can inform death investigation by helping to estimate the postmortem interval and build models to identify cause and manner of death. However, no attempts have been made to model potential microbial biomarkers in pediatric (≤2 years) deaths. This study provided a cross-sectional survey of the microbiota of 53 pediatric cases (black, white, both sexes) seen in Wayne County, Michigan. Autopsy cases represented accidents, homicides, or natural causes. Postmortem microbiome were collected by swabbing the eyes, ears, nose, mouth, umbilicus, brain, rectum, trabecular space, and cardiac blood. 16S rRNA sequence analyses indicated that sex, race, age, body site, and manner of death (MOD) had significant effects on microbiome composition, with significant interactions among MOD, race, and age. Amplicon sequence variants identified intra- and interhost dispersion of the postmortem microbiome depending on death circumstance. Among manners of death, non-accidental deaths were significantly distinct from all other deaths, and among body sites the rectum was distinct in its microbial composition. There is a real need for robust postmortem microbiome before it can be standardized as a practical tool for use in forensic investigation or public health. These results inform postmortem microbial variability during pediatric death investigation that contributes to a larger effort to understand the postmortem microbiome.

Three-dimensional (3D) measurement systems for firearm forensics are becoming more prevalent in forensic laboratories, and these instruments are typically coupled with algorithms to assist firearm examiners with comparisons. Due to differences in firearm feature reproducibility on different types of ammunition, comparison algorithms need to be tested utilizing a variety of ammunition brands. For this study, 30 shots were fired, utilizing six common ammunition brands, from each of the 10 casework firearms for a total of 300 cartridge cases. All cartridge cases were scanned on a Cadre Forensics TopMatch-GS 3D desktop system and compared using Cadre's breech face and firing pin aperture shear algorithms for a total of 44,850 comparisons. Receiver operating characteristic (ROC) curves and the area under the curve (AUC) were used to quantify the performance of the algorithms when comparing within and between ammunition brands. Same ammunition brand comparisons (AUC = 0.964) performed statistically significantly better (p = 0.0075) than different ammunition brand comparisons (AUC = 0.944). Overall, the results generally indicated greater reproducibility of characteristics from a firearm when the ammunition in a comparison is the same, however, Cadre's algorithms demonstrated excellent overall discrimination between same and different-source comparisons regardless of ammunition brand (AUC = 0.946). Additionally, score thresholds were evaluated for easier interpretation of what algorithm results mean for practitioners, where 68.6% of same-source comparisons resulted in a similarity score greater than 0.5. These results should assist the field in moving toward the use of algorithms to assist examiners in casework comparisons.

Of the various rules establishing a mental health clinician's legal duty to take precautions to protect their patient from harming others, the most common is the specificity rule that limits the protective duty to warn reasonably identifiable victims. The specificity rule is important wherein the main or only specified protective measure is warning the victim. In the last quarter century, Pennsylvania adopted the specificity rule from its Supreme Court Emerich decision. In its recent Maas decision, the Pennsylvania Supreme Court expanded the duty to apply to potential victims who are unnamed and unidentifiable except for living on the same floor as the patient of a multiunit building. Victims constituted a group referenced by the patient as a “neighbor,” but from the patient's threats both narrower “next door neighbor” and broader “anyone.” We place this judicial expansion of the duty to warn within the context of professional ethics guidelines and state Tarasoff statutes that pertain to psychiatrists. The potential adverse consequences of this vague expansion of the specificity rule for clinicians, psychiatric patients, and unconnected citizens of Pennsylvania and for other jurisdictions in which courts could misguidedly follow this expansionist example are discussed, along with potential solutions.

Early detection of submerged bodies is essential to increase the possibility of recovery. Different water bodies present different challenges, particularly rivers and the ocean, where chances of detection are vastly reduced. Modern recreational fish finders incorporate multiple sonar technologies, including Sidescan sonar, at high-frequency resolutions, similar to commercial units. Recreational units are widely available and usually hull-mounted, allowing them to be utilized on almost any vessel in shallow and difficult to navigate environments. Recreational fish finders are currently an untapped resource which may assist search teams with the early detection and recovery of human remains submerged in shallow water (<20 m). This research investigated the efficacy of a modern recreational fish finder attached to a kayak to detect human proxies and living human volunteers submerged at shallow depths in (1) two indoor freshwater environments and (2) two outdoor environments (a freshwater lake and a nearshore coastal environment). Results demonstrated that recreational fish finders can detect human bodies submerged in both fresh and saltwater contexts at shallow depths within the water column and on the water bottom. Recreational units equipped with Sidescan sonar (800 kHz) provided the necessary resolution for underwater body detection at shallow depths. These sophisticated sensors are currently used by recreational boaters and anglers, and offer the opportunity to increase the eyes in the water not just by search and recovery teams, but by the public itself.

Single view metrology poses a persistent challenge in extracting accurate quantitative information from individual images or video frames within the realm of forensic video analysis. Methods such as reverse projection, projective geometry, and photogrammetry have been used in the past with success but require validation and understanding of the limitations of each method. This study aims to conduct a preliminary validation of the subject height estimation feature in Amped FIVE software, which relies on the principles of single view metrology. A group of 14 individuals assumed an upright posture at distances of 2.4 m, 5.4 m, and 10 m away from two security cameras with different resolutions 4k (3840 × 2160) and HD (1920 × 1080). Prior to recording, participants’ heights were measured but were not provided to the researcher in this study until after the analysis was completed. A height scale with clearly marked black and white graduations was used as a control. Height estimations were subsequently obtained using the Measure 3D tool in Amped FIVE software. On average, the overall error was found to be approximately ± 1.3 cm with a standard deviation of 0.9 cm. This study shows that Amped FIVE can provide accurate height estimates in a controlled environment. Future work should be done to test more difficult scenarios in less-than-ideal conditions.

The inconclusive category in forensics reporting is the appropriate response in many cases, but it poses challenges in estimating an “error rate”. We discuss the use of a class of information-theoretic measures related to cross entropy as an alternative set of metrics that allows for performance evaluation of results presented using multi-category reporting scales. This paper shows how this class of performance metrics, and in particular the log likelihood ratio cost, which is already in use with likelihood ratio forensic reporting methods and in machine learning communities, can be readily adapted for use with the widely used multiple category conclusions scales. Bayesian credible intervals on these metrics can be estimated using numerical methods. The application of these metrics to published test results is shown. It is demonstrated, using these test results, that reducing the number of categories used in a proficiency test from five or six to three increases the cross entropy, indicating that the higher number of categories was justified, as it they increased the level of agreement with ground truth.

Aggressive chemicals intended for cleaning pools or unclogging drains contain high concentrations of dangerous compounds, leading to their nefarious use in dissolving human remains in some criminal cases. The use of these readily accessible household cleaners to destroy human remains and hide evidence of a crime presents a considerable challenge for human identification. However, research on the success of recovering DNA from such remains is limited. Therefore, we investigated the effects of submerging partial human remains (including whole heads, forearms, and hands) in five different household products: bleach, Rid-X® septic treatment, lye drain opener, sulfuric acid drain opener, and muriatic acid (hydrochloric acid) pool cleaner. We evaluated the impact of each chemical, focusing on visual changes, DNA recovery, and the potential for successful human identification through traditional STR or mitochondrial DNA analyses. Exposure to all chemicals altered the appearance of the remains, but DNA recovery was still possible across various time periods, up to 28 days. Human remains exposed to bleach, Rid-X®, and lye produced full STR profiles after 4 weeks. Sulfuric acid shortened this time to 3 weeks, while hydrochloric acid, the most damaging chemical, limited full STR profile recovery to just the first 3 days of exposure. This study demonstrates that although differences in the rate of damage occur depending on the amount of tissue introduced, volume of chemical used, and the specific chemical of choice, DNA-based human identification of remains treated with everyday household cleaners is likely, particularly if bone fragments are recovered.

People diagnosed with substance use disorder (SUD) might represent a high-risk subpopulation for New Psychoactive Drugs (NPS) consumption, and hair analysis offers a unique perspective to assess drug prevalence in this population. The present study aims to assess the prevalence of NPS and their co-consumption with traditional drugs of abuse (DoA) in individuals diagnosed with SUD. Hair samples from patients under care at the addiction treatment service of Bologna, Italy, for a diagnosed SUD, were collected during 2023 and analyzed by ultra-high-performance liquid chromatography-mass spectrometry (UHPLC–MS/MS), using a previously validated method. Among the 88 patients included, 95.5% tested positive for at least one substance, of which 88.1% for traditional DoA only, and 11.9% for NPS in addition to DoA. Among the positive samples, patients were found positive for more than two drugs in 67.9% of cases. The combination of DoA and NPS was more frequent in the younger age group (<21–30 years old, compared to 31–70, p = 0.025). Ketamine was detected in 8.0% of all samples, with mean hair levels 49.68 pg/mg (ranging 8.55–81.90 pg/mg) and was frequently accompanied by cocaine (85.7% of cases). Fentanyl was detected in 3.4% of all samples, while, among NPS, buphedrone was the only one detected. Our retrospective study highlights that the consumption of NPS is relatively low compared to other vulnerable or high-risk populations. However, the prevalence of polydrug consumption and the high rate of ketamine–cocaine combination warrant careful monitoring even in this population.

Venous aneurysms are rare, and their incidence is unknown. External iliac vein aneurysms are even more rare with only 50 case reports published from 1950 to 2018. We present a case of an individual who died suddenly from a pulmonary thromboembolic event due to an external iliac vein aneurysm formed by a remote penetrating injury. A 32-year-old male was in Immigration and Customs Enforcement (ICE) custody when he died suddenly. It was discovered during his autopsy that he had an occlusive pulmonary thromboembolism (PE) within the left main pulmonary artery and distal branches of the right pulmonary artery. On additional investigation and postmortem computed tomography, a large saccular aneurysm arising from the external iliac vein was discovered. This aneurysm contained clotted blood, and was determined to be the cause of his PE and subsequent death. Although rarely a source for a fatal PE, venous aneurysms should be considered as a possible source for thromboembolism; their presence may alter the manner of death, given their underlying etiology. This is especially true for young adults with a remote history of trauma near a major venous tributary, as traumatic arteriovenous fistula is a common cause of secondary venous aneurysm. For this case, the manner of death was classified as homicide.