Journal of forensic sciences最新文献

Facial identification examiners assess whether two facial images-such as an image of an unknown person from surveillance footage and a controlled image of a known individual-depict the same person or different people. To communicate their observations, they rely on predefined verbal articulation scales that sometimes have associated numeric equivalents. However, these terms have not been calibrated against the actual strength of the evidence except indirectly through proficiency tests and black box studies. The present research reanalyzes the findings of face comparisons from the most comprehensive facial identification black box study to date, as well as multiple facial examination proficiency tests, to generate a quantitative measure of the strength of the evidence for each comparison. We used an ordered probit model to summarize the distribution of responses of both individual examiners and examiner teams to produce a set of likelihood ratios for each group and test. The likelihood ratios can be lower than values implied by the evaluative statements, which do not seem to justify the strengths of evidence implied by current articulation scales used in facial comparisons. Our analyses suggest that examiners are using language that overstates the strength of the evidence by several orders of magnitude.

This case study reports the forensic identification of N-methylaniline (NMA) in an automotive gasoline sample seized from a gas station in Brazil, with a semi-quantitative estimate of ca. 1.9% (v/v), indicating a case of fuel adulteration. Although NMA has been investigated in experimental fuel formulations as a potential nonmetallic anti-knock additive capable of increasing octane rating, to the best available knowledge, no previous studies have reported its detection in real-world gasoline samples. In Brazil, the National Petroleum Agency (ANP) authorizes only previously approved additives, meaning that the presence of NMA constitutes a noncompliant fuel component. The sample was analyzed using gas chromatography-mass spectrometry (GC-MS), tandem mass spectrometry (MS/MS), and attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR). The compound was unambiguously identified and characterized, demonstrating the effectiveness of these complementary analytical techniques for detecting unapproved or unconventional additives in complex hydrocarbon matrices. This case underscores the relevance of forensic fuel analysis for regulatory compliance and highlights the need for continuous monitoring to mitigate health, environmental, and operational risks associated with aromatic amine contamination.

Juvenile firesetting remains underexamined in non-Western forensic populations. This study investigated the psychiatric, motivational, and familial characteristics of 55 adolescents (mean age = 15.05 years; 92.7% male) referred for court-ordered forensic psychiatric assessment in Turkey between 2019 and 2025. Structured coding captured motivational subtypes, family adversity, psychiatric diagnoses, co-occurring offending, and incident characteristics. Motivations included antisocial/criminal, anger- or revenge-driven, impulsive, curiosity-related, and distress-linked acts. Family adversity-particularly fragmented caregiving and neglect-was common, alongside high rates of conduct disorder, attention-deficit/hyperactivity disorder, and depression. Fires most frequently occurred at home or outdoors and were typically ignited with lighters. Recurrence occurred in 14.5% of cases and was more strongly associated with delinquent behavior patterns than with psychiatric diagnoses; co-occurring offending independently predicted recurrence (odds ratio = 7.78, p = 0.046). Findings highlight heterogeneous externalizing pathways shaped by cumulative family adversity and extend the international literature by providing forensic evidence from a non-Western context. Results may inform structured assessment and tailored intervention strategies within juvenile justice systems.

Evaluative activity level guidance cautions DNA analysts not to respond to courtroom questions asking "how" and "when" DNA was deposited. However, criminal defendants have the right to confront and cross-examine witnesses against them. Al-Atiyyat v. State is the first U.S. case to address whether a DNA analyst's refusal to answer an activity level question violates a defendant's Sixth Amendment right to confrontation. Under the circumstances described, the court ruled that it does not. This case report examines the Al-Atiyyat decision and provides a detailed description of both the trial and appellate courts' Sixth Amendment analysis, including their collective frustration with the analyst's refusal to respond to defense counsel's activity level question. That frustration is symptomatic of the tension between current scientific guidance on activity level testimony and U.S. legal standards that control such testimony-whether evaluative or informal. This case report compares existing activity level guidance with relevant case law that governs the scope of a DNA analyst's testimony. It concludes that a gap exists between current guidance and U.S. law, which considers DNA analysts both qualified to offer opinions on activity level questions and legally obligated to respond to defense questions on cross-examination. The parties should litigate anticipated activity level issues before trial, so the court can define the proper scope of anticipated questions and testimony. The U.S. forensic DNA community should publish substantive guidance for analysts faced with activity level questions first raised during trial that considers both scientific and relevant legal principles.

Psychopathy is a multidimensional disorder influenced by behavioral, social, and biological factors. Minor physical anomalies (MPAs) are subtle morphological variations that arise from developmental disruptions during the prenatal period and are considered potential phenotypic indicators of such neurodevelopmental irregularities. Previous research has examined several neurodevelopmental aspects of psychopathy. However, the specific relationship between MPAs and psychopathy has not yet been systematically investigated. This cross-sectional study investigated the association between MPAs and psychopathy levels. The sample comprised 114 male offenders meeting DSM-5 criteria for Antisocial Personality Disorder (ASPD) and 54 healthy controls matched for age and sex. Psychopathy was assessed using the Psychopathy Checklist-Revised, and participants were classified as low (LP) or high psychopathy (HP). MPAs were evaluated using the Waldrop Minor Physical Anomaly Scale. Results indicated that total, craniofacial, and peripheral MPA scores were significantly higher in the HP group than in LP and control groups (p < 0.001). Psychopathy level strongly correlated with total MPA score (r = 0.83, p < 0.001). Regression analysis showed that MPAs, particularly craniofacial anomalies, were stronger predictors of psychopathy than psychosocial factors (B = 0.710, p < 0.001). This study demonstrated a significant association between MPAs and the level of psychopathy. The findings suggest that lower levels of psychopathic traits are more closely related to psychosocial factors, whereas higher levels may be more strongly associated with craniofacial MPAs. Multicenter and longitudinal studies examining neurodevelopmental and psychosocial interactions may contribute to a deeper understanding of the developmental dynamics of psychopathy.

Trace DNA can be deposited onto a wide range of surface types which can include substrates with a coating of oil: examples being firearm components, power tools, and kitchen utensils. We report on the impacts of oil on DNA recovery and downstream DNA processing. Thumbprints were made on 60 separate glass slides, then stained with Diamond Dye and fluorescent cellular material counted as an estimation of the cells deposited. Aliquots of five different mineral oils, chosen due to their common uses and variation in viscosity, were spread across the entire deposited thumbprint. The thumbprints coated with one of the five oils were left at room temperature for either 1 day or 7 days. A swab was used to collect cellular material which was then processed manually through a DNA extraction process, quantified and STR alleles amplified using the VeriFiler™ Plus STR kit. It was observed that all five oils impacted the initial DNA recovery process by saturating the swab. The presence of oils also impacted the DNA extraction process by interacting with the magnetic resin. Oils with higher viscosity accentuated these observed effects during the DNA extraction process, as the presence of a white precipitate was seen to be carried over into the final eluate. A total of 56% of the 1-day samples and 72% of the 7-day samples resulted in DNA profiles comprised of 12 or more alleles. The results of this study highlighted the possible impacts of collecting samples with oils present on the surface.

This study evaluated the performance and limitations of the ForenSeq™ MainstAY chemistry on the MiSeq FGx® Sequencing System, which is approved for National DNA Index System (NDIS) use. This study included baseline performance, sensitivity and reproducibility studies, challenging casework samples, assessments of library plexities, comparisons with capillary electrophoresis (CE), standard versus enhanced PCR1 buffers, manual versus automated library preparation, and different flow cell types. To assess reproducibility across users, 33 samples were prepared by both an experienced and a novice user. Overall, the ForenSeq™ MainstAY Kit demonstrated high reliability with pristine samples and consistent performance across users, with minimal locus dropout until 62 pg. The kit outperformed CE for low-input and degraded samples, but limitations were observed at higher plexities. Increased sample numbers on a single flow cell disproportionately reduced read counts and locus recovery in degraded casework samples, while pristine samples were less affected. Strategic adjustments, such as batching degraded samples together or lowering plexity, may help mitigate these effects. Casework samples, including blood, touched items, bone, hair, and tissue, were tested with both standard and enhanced PCR1 buffers. In a 64-sample run (32 per buffer type), increased multiplexing reduced locus recovery in standard buffer samples, while the enhanced buffer improved recovery in 16 samples. Automated library preparation on the Opentrons OT-2 produced comparable or improved recovery relative to manual preparation, with no evidence of cross-contamination. These findings provide practical guidance for forensic laboratories adopting the MainstAY Kit, particularly in optimizing workflows for challenging samples and high-throughput sequencing environments.

Latent fingerprint research requires reproducible test materials that realistically mimic natural prints for the evaluation of development techniques. This study presents a novel artificial latent fingerprint solution that incorporates lipid components derived from the human body, simulating the composition of natural sweat and sebum, and combines them with traditional amino acid-based solutions. To improve solubility of non-polar lipid molecules, a 1:1 (v/v) mixture of n-hexane and isopropyl alcohol was used as the solvent, and the solution was loaded into printer cartridges to deposit standardized fingerprint-sized images on A4 paper, OHP film, and thermal paper. Development was carried out using established reagents, including ninhydrin, 1,2-indandione (1,2-IND), oil red O (ORO), and nile red (NR) for porous substrates; cyanoacrylate (CA) fuming with basic yellow 40 (BY 40), black, and fluorescent powders for nonporous substrates; and ThermaNin^®, 1,2-IND + polyvinylpyrrolidone (1,2-IND + PVP), ORO, and NR for thermal paper. The artificial prints showed broad compatibility across porous, nonporous, and thermal surfaces. Clear ridge detail and identifiable minutiae were consistently observed with most reagents, although NR exhibited limited fluorescence. All developed prints were identical, ensuring reproducibility for controlled testing. These findings demonstrate that the proposed solution provides a realistic and standardized tool for forensic validation of fingerprint development methods, including challenging substrates such as thermal paper.

This mixed-methods study investigates occupational burnout among forensic pathologists in Pakistan, incorporating a quantitative survey of 250 participants and qualitative interviews with 20 pathologists. This study investigated burnout using the Maslach burnout inventory (MBI) and qualitative interviews. As part of the quantitative analyses, independent-samples t-tests, ANOVAs, and MANOVA were conducted to examine the effects of gender, age, and professional experience on emotional exhaustion (EE), depersonalization (DP), personal accomplishment (PA), and total burnout. The interviews were thematically analyzed, providing context for the experiences being lived. The prevalence of burnout was average among most participants, with almost one-fifth of the respondents having high scores for EE and DP. Although the statistical tests did not indicate significant differences based on gender or age (ps > 0.05), professional experience was a significant predictor of PA, and more senior professionals reported higher resiliency and a reduced rate of burnout. These findings were replicated in the qualitative results, with heavy caseloads, poor institutional support, and trauma exposure being the main stressors. The main protective mechanisms are resilience, mentorship, faith, and family support. Burnout has adverse effects on forensic performance, which contributes to delays in reporting, mistakes, and threats to medicolegal reliability. Forensic pathology burnout is quantifiable and has specific outcomes. Caseload and institutional culture remained significant predictors, with resilience and mentorship serving as protective factors. To resolve burnout, the organization needs to change and implement relevant changes, redistribute the workloads, and acknowledge that mental health is a part of maintaining stable forensic practice.

When sexual assault evidence kits do not yield biological evidence demonstrating sexual contact, clothing such as undergarments is evaluated for the presence of semen. Menstrual underwear is a new type of undergarment and feminine product encountered as evidence in sexual assaults. They are composed of absorbent and leak-proof layers and can be washed and re-worn multiple times. The objective of this work was to determine a best practice for semen and DNA recovery from reusable menstrual underwear. Simulated postcoital samples were deposited on three different brands of menstrual underwear, and alternate light source evaluation failed for two of the three brands tested, though acid phosphatase testing was positive for all three brands tested. Testing of individual layers versus cuttings of a portion of the stain found that a full-depth cutting results in optimal biological sample recovery. Mock postcoital deposits were then washed once or twice and subjected to serological and DNA workflows, with varying results in acid phosphatase and P30 testing after washing once or twice between brands. However, sperm recovery was successful in all samples, and complete short tandem repeat (STR) profiles were obtained from both sperm and nonsperm fractions from all samples, regardless of washing status. With these findings, while sperm recovery has the highest likelihood of success with a full-thickness cutting, forensic scientists should be cautious in depending on ALS for stain location. Additionally, biological materials remain in these brands of menstrual underwear after washing, and therefore, biological material from previous sexual contact could remain and be detectable.