Portable high‐resolution automated 3D imaging for footwear and tire impression capture

The forensic science community raised the need for improved evidence recognition, collection, and visualization analytical instrumentation for field and laboratory use. While the 3D optical techniques for imaging static objects have been extensively studied, there is still a major gap between current knowledge and collecting high‐quality footwear and tire impression evidence. Among optical means for 3D imaging, digital fringe projection (DFP) techniques reconstruct 3D shape from phase information, achieving camera‐pixel spatial resolution. This paper presents a high‐resolution 3D imaging technology using DFP techniques dedicated to footwear and tire impression capture. We developed fully automated software algorithms and a graphical user interface (GUI) that allow anyone without training to operate for high‐quality 3D data capture. We performed accuracy evaluations and comparisons comparing with the commercial high‐end 3D scanner and carried out qualitative tests for various impressions comparing with the current practices. Overall, our technology achieves similar levels of accuracy and resolution with a high‐end commercially available 3D scanner, while having the merits of being (1) more affordable; (2) much easier to operate; and (3) more robust. Compared with the current practice of casting, our technology demonstrates its superiority because it (1) is non‐destructive; (2) collects more evidence detail than casts, especially when an impression is fragile; (3) requires less time and money to collect each piece of evidence; and (4) results in a digital file that can easily be shared with other examiners.     

The Prevalence of Mental Illness Among Inmates in a Rural State

A limited number of recent empirical studies suggest that inmates suffer from high rates of serious mental illness. Different explanations are offered depending on the type of institution: jail or prison. The literature is based largely on urban samples and does not offer comparisons of rates across types of institution within a single study. The present study examined a random sample of 213 jail and prison inmates in a rural state using the Diagnostic Interview Schedule (III-R). Among jail inmates there was little evidence of high rates of serious mental illness, suggesting the criminalization of mental illness may not be as evident in rural settings as urban areas. Among prison inmates, however, high rates of mental disorders were found, supporting previous findings in urban and rural jurisdictions. Implications of the findings are discussed in the context of a consolidated correctional system.     

Collusion in auctions for emission permits: An experimental analysis

Environmental markets have several institutional features that provide a new context for the use of auctions and that have not been studied previously. This paper reports on laboratory experiments testing three auction forms—uniform and discriminatory price sealed‐bid auctions and an ascending clock auction. We test the ability of subjects to tacitly or explicitly collude in order to maximize profits. Our main result is that the discriminatory and uniform price auctions produce greater revenues than the clock auction, both with and without explicit communication. The clock appears to facilitate successful collusion, both because of its sequential structure and because it allows bidders to focus on one dimension of cooperation (quantity) rather than two (price and quantity).© 2009 by the Association for Public Policy Analysis and Management.     

Managing Racial Diversity: Matching Internal Strategies with Environmental Needs

Although demographic diversity has been of paramount concern to researchers and practitioners in public management, studies exploring managerial strategies to capitalize on and respond to the needs of diverse client populations are scarce. This article examines strategies for managing diversity as a way to buffer environmental challenges in service delivery and performance resulting from heterogeneous client demands. Findings suggest that administrators prioritize diversity efforts when faced with higher levels of regulatory violations (a performance measure). A higher percentage of black residents is associated with lower service quality. However, the effect of managerial strategies for diversity on performance is conditioned by the racial composition of the clients: as the percentage of black nursing home residents increases, diversity management efforts are associated with a lower number of regulatory violations. Similarly, at higher levels of racial heterogeneity, diversity management efforts are associated with fewer regulatory violations.     

Experimental results on data analysis algorithms for extracting and interpreting edge feature data for duct tape and textile physical fit examinations

A physical fit is an important observation that can result from the forensic analysis of trace evidence as it conveys a high degree of association between two items. However, physical fit examinations can be time-consuming, and potential bias from analysts may affect judgment. To overcome these shortcomings, a data analysis algorithm using mutual information and a decision tree has been developed to support practitioners in interpreting the evidence. We created these tools using data obtained from physical fit examinations of duct tape and textiles analyzed in previous studies, along with the reasoning behind the analysts' decisions. The relative feature importance is described by material type, enhancing the knowledge base in this field. Compared with the human analysis, the algorithms provided accuracies above 90%, with an improved rate of true positives for most duct tape subsets. Conversely, false positives were observed in high-quality scissor cut (HQ-HT-S) duct tape and textiles. As such, it is advised to use these algorithms in tandem with human analysis. Furthermore, the study evaluated the accuracy of physical fits when only partial sample lengths are available. The results of this investigation indicated that acceptable accuracies for correctly identifying true fits and non-fits occurred when at least 35% of a sample length was present. However, lower accuracies were observed for samples prone to stretching or distortion. Therefore, the models described here can provide a valuable supplementary tool but should not be the sole means of evaluating samples.     

Do bone elasticity and postmortem interval affect forensic fractographic analyses?

Forensic fractographic features of bone reliably establish crack propagation in perimortem injuries. We investigated if similar fracture surface features characterize postmortem fractures. Experimentally induced peri- and postmortem fractures were used to assess if fractographic features vary as bone elasticity decreases during the postmortem interval (PMI). Thirty-seven unembalmed, defleshed human femoral shafts from males and females aged 33–81 years were fractured at varying PMIs with a drop test frame using a three-point bending setup and recorded with a high-speed camera. Vital statistics, cause of death, PMI length, temperature, humidity, collagen percentage, water loss, fracture energy, and fractography scores were recorded for each sample. Results showed that fractographic features associated with perimortem fractures were expressed in PMIs up to 40,600 accumulated degree hours (ADH), or 60 warm weather days. Hackle was the most consistently expressed feature, occurring in all fractures regardless of ADH. The most variable characteristics were wake features (78.4%) and arrest ridges (70.3%). Collagen percentage did not correlate strongly with ADH (r = −0.04, p = 0.81); however, there was a strong significant correlation between ADH and water loss (r = 0.74, p < 0.001). Multinomial logistic regression showed no association between fractographic feature expression and ADH or collagen percentage. In conclusion, forensic fractographic features reliably determine initiation and directionality of crack propagation in experimentally induced PMIs up to 40,600 ADH, demonstrating the utility of this method into the recent postmortem interval. This expression of reliable fractographic features throughout the early PMI intimates these characteristics may not be useful standalone features for discerning peri- versus postmortem fractures.     

Potency levels of regulated cannabis products in Michigan 2021–2022

Evaluation of cannabinoid concentrations in products from the legal cannabis market has been fraught with uncertainty. The lack of standardized testing methodology and the susceptibility of cannabinoids to degradation under certain storage conditions complicates the efforts to assess total tetrahydrocannabinol (THC) levels across wide geographic areas. There are few peer-reviewed surveys of cannabinoid concentrations in regulated products. Those that have been done have not characterized the effects of differences in analytical methodology, sample population, and storage conditions. Viridis Laboratories, which operates two cannabis safety compliance facilities in Michigan, has analyzed over 34,000 cannabis products throughout 2021 and 2022 before the sale in the regulated market. Fifteen cannabinoids in cannabis flower, concentrates, and infused products were tested using methanolic extraction and analysis by high-performance liquid chromatography with diode-array detection. Methods were validated before use, and the flower analysis procedure was certified by the Association of Analytical Collaboration. All the samples were tested before submission for sale and therefore had not undergone prolonged storage. The results are compared with those seen in other states as well as in the illicit market. Total THC levels in cannabis flower from the regulated market are significantly higher than those seen in illicit products. The distribution of cannabinoid levels is similar in flowers intended for either the medicinal or adult-use markets, with an average potency of 18%–23% of total THC. Total THC in concentrates averages up to 82%. Other cannabinoids are observed at significant levels, mostly in products specifically formulated to contain them. These results may act as a benchmark for potency levels in the regulated market.     

Medical examiner response to the drug overdose epidemic in King County Washington: “Real-time” surveillance,data science,and applied forensic epidemiology

As the overdose epidemic overwhelmed medicolegal death investigation offices and toxicology laboratories, the King County Medical Examiner's Office responded with “real-time” fatal overdose surveillance to expedite death certification and information dissemination through assembling a team including a dedicated medicolegal death investigator, an information coordinator, and student interns. In-house testing of blood, urine, and drug evidence from scenes was performed using equipment and supplies purchased for surveillance. Collaboration with state laboratories allowed validation. Applied forensic epidemiology accelerated data dissemination. From 2010 to 2022, the epidemic claimed 5815 lives in King County; the last 4 years accounted for 47% of those deaths. After initiating the surveillance project, in-house testing was performed on blood from 2836 decedents, urine from 2807, and 4238 drug evidence items from 1775 death scenes. Time to complete death certificates decreased from weeks to months to hours to days. Overdose-specific information was distributed weekly to a network of law enforcement and public health agencies. As the surveillance project tracked the epidemic, fentanyl and methamphetamine became dominant and were associated with other indicators of social deterioration. In 2022, fentanyl was involved in 68% of 1021 overdose deaths. Homeless deaths increased sixfold; in 2022, 67% of 311 homeless deaths were due to overdose; fentanyl was involved in 49% and methamphetamine in 44%. Homicides increased 250%; in 2021, methamphetamine was positive in 35% of 149 homicides. The results are relevant to the value of rapid surveillance, its impact on standard operations, selection of cases requiring autopsy, and collaboration with other agencies in overdose prevention.     

Fatal intoxication involving 2-methyl AP-237

Novel synthetic opioids contribute considerably to the opioid epidemic, especially with the frequent emergence of structurally similar compounds. This case report describes a fatal intoxication involving 2-methyl AP-237. A 54-year-old Caucasian male was found deceased from an apparent drug overdose. A plastic container labeled “2MAP” and a cut straw were found in the decedent's backpack at the scene. A white substance found in the container tested positive for fentanyl by field testing. According to his medical history, the decedent was treated for a drug overdose 3 years prior to his death. With no diagnostic findings at autopsy, the case was submitted for toxicological analysis. An unknown substance was detected in peripheral blood and urine using gas chromatography with nitrogen phosphorous detection (GC-NPD). Further testing was conducted using gas chromatography–mass spectrometry (GC–MS) and liquid chromatography-quadrupole-time-of-flight mass spectrometry (LC-QTOF-MS) which confirmed the presence of 2-methyl AP-237 and potential metabolites in blood and urine. Quantitation by GC-NPD revealed concentrations of 2-methyl AP-237 in blood and urine at 480 ng/mL and 4200 ng/mL, respectively. The toxicological analysis also identified and quantitated alprazolam in the blood at 55 ng/mL. Additionally, the metabolism of 2-methyl AP-237 was investigated and three hydroxylated metabolites were identified in peripheral blood and urine. Limited literature is available for the detection and quantitation of 2-methyl AP-237 in postmortem specimens. Given the toxicological findings with unremarkable autopsy findings, this case is an example of a fatal intoxication involving 2-methyl AP-237.     

Evaluation of canine training aids containment for homemade explosive and components by headspace analysis and canine testing

While canines are most commonly trained to detect traditional explosives, such as nitroaromatics and smokeless powders, homemade explosives (HMEs), such as fuel–oxidizer mixtures, are arguably a greater threat. As such, it is imperative that canines are sufficiently trained in the detection of such HMEs. The training aid delivery device (TADD) is a primary containment device that has been used to house HMEs and HME components for canine detection training purposes. This research assesses the odor release from HME components, ammonium nitrate (AN), urea nitrate (UN), and potassium chlorate (PC), housed in TADDs. Canine odor recognition tests (ORTs) were used with analytical data to determine the detectability of TADDs containing AN, UN, or PC. Headspace analysis by gas chromatography/mass spectrometry (GC/MS) with solid-phase microextraction (SPME) or online cryotrapping were used to measure ammonia or chlorine, as well as other unwanted odorants, emanating from bulk AN, UN, and PC in TADDs over 28 weeks. The analytical data showed variation in the amount of ammonia and chlorine over time, with ammonia from AN and UN decreasing slowly over time and the abundance of chlorine from PC TADDs dependent on the frequency of exposure to ambient air. Even with these variations in odor abundance, canines previously trained to detect bulk explosive HME components were able to detect all three targets in glass and plastic TADDs for at least 18 months after loading. Detection proficiency ranged from 64% to 100% and was not found to be dependent on either age of material.