Journal of forensic sciences最新文献

During the analysis of a commingled human remains assemblage, pair-matching is often conducted as part of the inventory to inform the DNA sampling strategy and to calculate the minimum or most likely number of individuals. As commingled assemblages become larger, pair-matching becomes more difficult, and it is unknown whether accuracy declines. Therefore, a study to determine the accuracy rates of visual pair-matching for multiple observers was conducted on a large, commingled human assemblage. The sample consisted of 580 left and right humeri (n = 287 and n = 293, respectively) from the commingled remains of the USS Oklahoma, which were undergoing analysis at the Defense POW/MIA Accounting Agency. Five anthropologists completed this study, determining humeri pairs with varying degrees of confidence and non-pairs. The overall precision was 81.0% and ranged from 74.1% to 95.9% for participants, including all confidence levels. When considering only confident matches, the overall precision for all participants increased to 91.4%.

Individuals who commit criminal behaviors are often thought to prioritize short-term goals rather than long-term goals (i.e., a present vs. a future time orientation). Though previous theories of crime and empirical research support a relationship among future time orientation, criminal thinking, and illegal behaviors, there is disagreement in the literature about how to operationalize the multidimensional construct of future time orientation. The primary aim of this pre-registered survey study was to measure multiple components of future time orientation to better understand the relationship with criminality-related outcomes. Participants were 248 undergraduate college students. Survey materials included a measure of impulsivity (Barratt Impulsiveness Scale-11), self-control (Brief Self-Control Scale), delay discounting (Monetary Choice Questionnaire), and Carstensen's Future Time Perspective Scale. Participants also completed two measures of criminal thinking style (the Texas Christian University Criminal Thinking Scale, the Criminogenic Cognitions Scale) and an illegal behaviors checklist. Bivariate results demonstrated a negative relationship between future time orientation (i.e., low impulsivity, high self-control, high future time perspective) and criminal thinking style. The relationship between delay discounting and criminal thinking was in the hypothesized direction but failed to reach statistical significance. Multiple regression analyses indicated that the measure of self-control had the most consistent and incrementally significant relationship with both criminal thinking style and illegal behaviors. Theoretical and practical implications of the results are discussed along with study limitations and future directions.

A person's age estimation from biological evidence is a crucial aspect of forensic investigations, aiding in victim identification and criminal profiling. In this study, we present a novel approach of utilizing Attenuated Total Reflection Fourier Transform Infrared (ATR FT-IR) spectroscopy to predict the age of donors based on nail samples. A diverse dataset comprising nails from donors spanning different age groups was analyzed using ATR FT-IR, with subsequent multivariate analysis techniques used for age prediction. The developed partial least squares regression (PLS-R) model demonstrated promising accuracy in age estimation, with a root mean square error of prediction (RMSEP) equal to 11.1 during external validation. Additionally, a partial least squares discriminant analysis (PLS-DA) classification model achieved high accuracy of 88% in classifying donors into younger and older age groups during external validation. This proof-of-concept study highlights the potential of ATR FT-IR spectroscopy as a non-destructive and efficient tool for age estimation in forensic investigations, offering a new approach to forensic analysis with practical implications.

Insects have long played a role in forensic investigations and can be used to estimate minimum time since death, corpse translocation, and link an individual to a crime scene. Bed bugs (Cimex lectularius) are wingless ectoparasitic insects of potential forensic utility, given that all mobile life stages feed on vertebrate blood. Successful profiling of autosomal short tandem repeats (STRs) from human DNA isolated from bed bugs has been previously reported. This proof-of-concept study looked to expand this work and determine any possible limitations of using bed bugs for both rapid stain identification (RSID™) for human blood and Y-STR profiling. To achieve this, bed bugs were fed either human male only or human pooled (female:male) blood for 30 min and subsequently collected at 12-h intervals up to 108 h post-blood meal (PBM). RSID™ blood testing was successful from the bed bug carcass remaining after DNA isolation, regardless of blood meal type and time of collection PBM. Complete Y-STR profiles were generated from bed bugs <60 h PBM. As the time PBM increased, DNA quantity decreased, while the degradation index increased. Collection of bed bugs at a crime scene could provide a valuable source of human blood for Y STR profiling and be used to link an individual to a crime scene or for potential male suspect exclusion. Future studies should look to replicate the results of this proof-of-concept study with larger numbers of bed bugs, more diverse blood donors, and additional STR profiling kits.

Within anatomical willed body programs and skeletal collections, whole bodies and their disassociated limbs and organs are identified and tracked. However, if these tracking mechanisms fail, DNA recovered from the formalin-fixed tissues/organs could provide an additional layer of quality assurance. Embalming fluids preserve biological tissues; however, they also damage, fragment, and cross-link DNA and protein molecules. This project investigated the success of STR-typing from various soft tissue and bone samples that were fixed with embalming solutions with a range of formaldehyde concentrations. Formalin-fixed samples dissected from five cadavers, including skin, muscle, bone, heart, and kidney were used in Phase 1 of this study. In Phase 2, an additional 57 tissue samples from various embalmed organs and body parts were collected to demonstrate long-term fixation and direct applicability within a body donor program. DNA was extracted from the samples using the QIAamp® FFPE Tissue Kit (QIAGEN), quantified with the Investigator® QuantiPlex® Pro RGQ qPCR Kit (QIAGEN), and amplified using the Investigator® 24plex and 26plex QS Kits and the Investigator® DIPplex Kit (QIAGEN). The results show the DNA was severely damaged, degraded, and often in low amounts (after one year post-embalming). Sampling from skin and muscle tissues embalmed with ~2.5%-5% formaldehyde solutions appears to be the best strategy for identification, while also maintaining the preservation of the tissues. The results of this project can provide informative data when determining which genotyping strategy may be best suited for the identification, re-association, and establishment of a database for the provenance of formalin-fixed human remains.