Quantitative evaluation of volatile hydrocarbons in post-mortem blood in forensic autopsy cases of fire-related deaths

Volatile hydrocarbons in post-mortem blood from victims of fires were analyzed quantitatively by headspace gas chromatography mass spectrometry. The benzene and styrene concentrations in the blood were positively correlated with the carboxyhemoglobin (CO-Hb) concentration, which is evidence that the deceased inhaled the hydrocarbons and carbon monoxide simultaneously. By contrast, the concentrations of toluene and CO-Hb in the blood were not significantly correlated. This lack of correlation could be explained by two different sources of toluene, with low blood concentrations of toluene arising when the deceased inhaled smoke and high blood concentrations of toluene arising when the deceased inhaled petroleum vapor or other unknown vapors. The quantity of soot deposited in the respiratory tract was classified into four grades (-, 1+, 2+, 3+). The mean CO-Hb concentration in the 1+ soot group was significantly lower than those in the 2+ (p<0.05) and 3+ (p<0.01) soot groups. The blood CO-Hb concentrations in the 1+ soot group were all below 30%. Those indicated that the deceased aspirated smoke that contained both soot and carbon monoxide. The wide variation in CO-Hb concentrations for each soot classification could be caused by the different types of smoke produced by different materials. For example, petroleum combustion with a limited supply of oxygen, like in a compartment fire, may produce a large volume of dense black smoke that contains a large quantity of soot. Soot deposits in the airways and the blood CO-Hb concentration are basic and essential autopsy findings that are used to investigate fire-related deaths. The quantitative GC-MS analysis of blood volatile hydrocarbons can provide additional useful information on the cause of the fire and the circumstances surrounding the death. In combination, these three findings are useful for the reconstruction of cases.     

Family Drug Treatment Courts As Comprehensive Service Models: Cost Considerations

Literature on family drug treatment courts (FDTCs) suggests that parental participation in these courts is associated with improved substance abuse treatment and child welfare system outcomes. Despite these beneficial outcomes, FDTCs serve only 7‐10% of eligible child welfare involved families. As part of a FDTC evaluation, this FDTC site sought to provide stakeholders with information about costs and benefits. Considering the program costs alongside the cost avoidance from reduced time in foster care, this analysis determined that FDTC participation resulted in a net savings per child of $9,710. The cost component of the evaluation proved valuable, challenging, and informative.     

A novel method for sorting and reassociating commingled human remains using deviation analysis

This study provides an innovative and novel method for sorting commingled human remains at the sacroiliac joint using deviation analyses. Virtual models were created at the University of Tennessee-Knoxville Donated Skeletal Collection from 69 os coxae and 66 sacra using an EinScan-Pro 2× + Handheld Surface Scanner. The shape of the auricular surfaces was analyzed in Geomagic Wrap 2017, and the congruency of the two auricular surfaces was measured using a deviation analysis. ROC curves were performed on a reference sample composed of 200 commingled and non-commingled joint pairs to identify threshold values that could help sort the commingled remains. A validation sample of 225 pairs was subsequently analyzed to demonstrate the efficacy of this new method on a sample of unknown individuals. Statistical analyses demonstrated that the deviation analysis values from sacroiliac joints of commingled pairs were significantly larger than those from non-commingled individuals (p < 0.0001). Based on the selected threshold values, 98%–100% of pairs were correctly sorted and reassociated. This novel and objective technique improves upon previously subjective strategies for sorting commingled remains and, in the future, will be applied to additional joint surfaces.     

Alternative direct-to-amplification cell lysis techniques for forensically relevant non-sperm cells

While efforts have been made to reduce the pervasive backlog of sexual assault evidence collection kits, the actual laboratory process remains very time-consuming due to the requirement of a differential lysis step before DNA purification, as well as intricate mixture analysis towards the end of the DNA workflow. Recently, an alternative, direct-to-amplification sperm lysis method (using 1 M NaOH) was identified. However, a direct cell lysis method for non-sperm cells has not been identified yet. Thus, the primary objective of this work was to find an alternative method that is quick, inexpensive, and does not require multiple purification steps for the lysis of non-sperm cells in sexual assault samples. In this study, vaginal swab samples were lysed with the control method, prepGEM™, as well as six alternative reagents: alkaline buffer with 25–200 mM NaOH, high-salt stain extraction buffer, modified radioimmunoprecipitation assay (RIPA) buffer, mammalian protein extraction reagent (M-PER™), digitonin buffer, and urea/thiourea buffer. Quantification using Quantifiler® Trio of vaginal and semen lysates revealed that the alkaline (25 mM NaOH) and M-PER™ methods were efficient for the lysis of vaginal epithelial cells without substantial sperm cell lysis. Following quantification, analysis of STR profiles from vaginal lysates revealed that the M-PER™ method showed promising results across all metrics examined, including the percentage of detected STR alleles, mean peak heights, peak height ratio, and interlocus balance. Thus, this method was recommended as an alternative to the traditional differential lysis method for non-sperm cells given its ability to produce amplification-ready lysates without any DNA purification step.     

The effects of certain intermediary target materials and their proximity to ballistic gelatin on jacketed hollow point bullet expansion

Expanding bullets are preferred by law enforcement because of their wounding potential and ability to avoid over-penetration which could result in unintended targets being struck by bullets that perforate their intended targets. Expansion failure for jacketed hollow point (JHP) bullets is commonly attributed to several causes including damage to the bullet's cavity, velocity loss, bullet destabilization and materials from intermediate targets filling the bullet's cavity which can cause expansion failure when the bullet subsequently impacts a soft, fluid-based target such as human tissue or ballistic gelatin. In this study, JHP bullets were fired into ballistic gelatin after passing through selected intermediate targets representing items common to shooting incidents. Velocity loss and bullet destabilization were not factors that contributed to the JHP bullets that experienced expansion failure; however, materials obstructing the bullets' cavities and damage to the bullets' cavities were considered causes for some of the JHP bullet expansion failures. It was determined through this research that most of the target materials caused JHP bullet expansion failure when shored against the ballistic gelatin, but when placed at distances of 7 ft. from the ballistic gelatin, bullets fired through the same target materials did expand. This original and unique study produced findings that are of significant value to shooting incident reconstruction experts and other forensic professionals as shooting incidents can call into question a victim's proximity to a wall or door when a bullet(s) perforated such a target material.     

Evaluation of the (hu)MANid program for sex and ancestry estimation in a diverse,contemporary CT scan-based sample

Human remains from forensic and bioarcheological contexts are often fragmentary, requiring methods for estimating a forensic profile that are based upon limited skeletal features. In 2017, Berg and Keryhercz created an online application, (hu)MANid, that provides sex and ancestry estimation from mandibular morphoscopic traits and linear measurements. In this study, we examine the utility of the (hu)MANid application in a diverse, urban US adult sample (aged 20–45; n = 143) derived from computed tomography (CT) scans. We secondarily conduct a preliminary analysis of the program's utility in a sample of adolescents (aged 15–17; n = 40). Six morphoscopic, and eleven morphometric traits were recorded as directed by the literature associated with the (hu)MANid program. Percent correct classification and posterior predictive values were calculated for the sex and ancestry estimations output by the program; chi-squared tests were employed to compare self-reported and predicted ancestry. In the adult sample, sex was accurately predicted for 75.52% of the sample. Ancestry prediction, however, was less favorable ranging from 19.3% to 50% correct. For the adolescent sample, correct sex estimation (45%) did not surpass what could occur by chance alone, though ancestry prediction fared better than in the larger adult sample (percent correct prediction overall average: 47.5%, range 35.71%–71.43%). The (hu)MANid application shows utility for use with CT scan-derived adult samples for sex estimation, but caution is warranted for ancestry estimation and use with samples that may not have reached full adult maturity.     

On the challenge of unambiguous identification of fentanyl analogs: Exploring measurement diversity using standard reference mass spectral libraries

Fentanyl analogs are a class of designer drugs that are particularly challenging to unambiguously identify due to the mass spectral and retention time similarities of unique compounds. In this paper, we use agglomerative hierarchical clustering to explore the measurement diversity of fentanyl analogs and better understand the challenge of unambiguous identifications using analytical techniques traditionally available to drug chemists. We consider four measurements in particular: gas chromatography retention indices, electron ionization mass spectra, electrospray ionization tandem mass spectra, and direct analysis in real time mass spectra. Our analysis demonstrates how simultaneously considering data from multiple measurement techniques increases the observable measurement diversity of fentanyl analogs, which can reduce identification ambiguity. This paper further supports the use of multiple analytical techniques to identify fentanyl analogs (among other substances), as is recommended by the Scientific Working Group for the Analysis of Seized Drugs (SWGDRUG).     

The effectiveness of various strategies to improve DNA analysis of formaldehyde-damaged tissues from embalmed cadavers for human identification purposes

Formalin-fixed tissues provide the medical and forensic communities with alternative and often last resort sources of DNA for identification or diagnostic purposes. The DNA in these samples can be highly degraded and chemically damaged, making downstream genotyping using short tandem repeats (STRs) challenging. Therefore, the use of alternative genetic markers, methods that pre-amplify the low amount of good quality DNA present, or methods that repair the damaged DNA template may provide more probative genetic information. This study investigated whether whole genome amplification (WGA) and DNA repair could improve STR typing of formaldehyde-damaged (FD) tissues from embalmed cadavers. Additionally, comparative genotyping success using bi-allelic markers, including INDELs and SNPs, was explored. Calculated random match probabilities (RMPs) using traditional STRs, INDEL markers, and two next generation sequencing (NGS) panels were compared across all samples. Overall, results showed that neither WGA nor DNA repair substantially improved STR success rates from formalin-fixed tissue samples. However, when DNA from FD samples was genotyped using INDEL and SNP-based panels, the RMP of each sample was markedly lower than the RMPs calculated from partial STR profiles. Therefore, the results of this study suggest that rather than attempting to improve the quantity and quality of severely damaged and degraded DNA prior to STR typing, a more productive approach may be to target smaller amplicons to provide more discriminatory DNA identifications. Furthermore, an NGS panel with less loci may yield better results when examining FD samples, due to more optimized chemistries that result in greater allelic balance and amplicon coverage.