A Novel Solvent-based Method to Separate Duct Tape from Porous Surface for Fingerprint Development

In this study, we have proposed a novel solvent-based method using a specific concentration of 3M™ Novec™ HFE-72DE and 7200 solvents to untangle duct tape from porous article with minimal impact to the quality of latent fingerprint deposited on the sticky-side surface of duct tape. A series of experiments determined that a mixture of 30% HFE-72DE:7200 (v/v) was found to be the most effective to separate various brands of duct tape from different types of porous surface, including office copy paper, newspaper, cardboard, and tissue wipe, which had been stored for up to 30 days before untangling. Further studies also revealed that 30% HFE-72DE:7200 was compatible with three common fingerprint development methods for porous articles, namely ninhydrin, indanedione-zinc, and physical developer. The nonflammability and low toxicity nature of this novel solvent mixture also make it ideal for separating duct tape from porous surface in laboratory or at crime scene.     

Suicide by Close-Range Gunshot Wound to the Bridge of the Nose

Suicidal gunshot wounds to the nasal bridge are rare, particularly at close range (defined as muzzle of the weapon not touching the skin surface, but near enough to deposit soot and stippling). Previously reported suicidal gunshot wounds to the nose have been through the left nostril (Forensic Sci Int 1995;71(1):25–31; J Forensic Radiol Imag 2013;1(2):63–7). The death of a 26-year-old man with a close-range gunshot wound to the bridge of the nose was deemed suicide due to history, scene, and autopsy findings. These findings included previous suicidal ideation, texted and written notes, the decedent's cross-legged position seated on the floor, the trajectory of the bullet through his head and into the ceiling fan and roof above him, and acute alcohol intoxication. This decedent may have been intending a hard contact forehead location but inadvertently fired the gun into the bridge of his nose while bending forward, prior to contact.     

Strength in Numbers or Quality over Quantity? Examining the Importance of Criterion Measure Selection to Define Validity Groups in Performance Validity Test (PVT) Research

Mirroring clinical guidelines, recent Performance Validity Test (PVT) research emphasizes using ≥ 2 criterion PVTs to optimally identify validity groups when validating/cross-validating PVTs; however, even with multiple measures, the effect of which specific PVTs are used as criterion measures remains incompletely explored. This study investigated the accuracy of varying two-PVT combinations for establishing validity status and how adding a third PVT or applying more liberal failure cut-scores affects overall false-positive (FP)/-negative (FN) rates. Clinically referred veterans (N = 114; 30% clinically identified as invalid) completing a six-PVT protocol as during their evaluation were included. Concordance rates were calculated across all possible two-and three-PVT combinations at conservative and liberal cutoffs. Two-PVT combinations classified 72–91% of valid (0–4% FPs) and 17–74% of invalid (0–40% FNs) cases, and three-PVT combinations classified 67–86% of valid (0–6% FPs) and 57–97% of invalid (0–24% FNs) at conservative cutoffs. Liberal cutoffs classified 53–86% of valid (0–15% FPs) and 39–82% of invalid (0–30% FNs) cases for two-PVT combinations and 46–75% of valid (3–27% FPs) and 60–97% of invalid (0–17% FNs) cases for three-PVT combinations. Irrespective of whether a two-or three-PVT combination or conservative/liberal cutoffs were used, many valid and invalid cases failed only one PVT (3–68%).Two-PVT combinations produced high FNs and were less accurate than three-PVTs for detecting invalid cases, though variable accuracy was found within both types of combinations based on the specific PVTs in the combination. Thus, both PVT quantity and quality are important for accurate validity classification in research studies to ensure reliability and replicability of findings. Applying more liberal cutoffs yielded increased sensitivity, but with generally higher FPs yielding problematic specificity, particularly for three-PVT combinations.     

The 2018 California Wildfires: Integration of Rapid DNA to Dramatically Accelerate Victim Identification

In November 2018, Butte County, California, was decimated by the Camp Fire, the deadliest wildfire in state history. Over 150,000 acres were destroyed, and at its peak, the fire consumed eighty acres per minute. The speed and intensity of the oncoming flames killed scores of people, and weeks before the fire was contained, first responders began searching through the rubble of 18,804 residences and commercial buildings. As with most mass disasters, conventional identification modalities (e.g., fingerprints, odontology, hardware) were utilized to identify victims. The intensity and duration of the fire severely degraded most of the remains, and these approaches were useful in only 22 of 84 cases. In the past, the remaining cases would have been subjected to conventional DNA analysis, which may have required months to years. Instead, Rapid DNA technology was utilized (in a rented recreational vehicle outside the Sacramento morgue) in the victim identification effort. Sixty-nine sets of remains were subjected to Rapid DNA Identification and, of these, 62 (89.9%) generated short tandem repeat profiles that were subjected to familial searching; essentially all these profiles were produced within hours of sample receipt. Samples successfully utilized for DNA identification included blood, bone, liver, muscle, soft tissue of unknown origin, and brain. In tandem with processing of 255 family reference samples, 58 victims were identified. This work represents the first use of Rapid DNA Identification in a mass casualty event, and the results support the use of Rapid DNA as an integrated tool with conventional disaster victim identification modalities.     

Population drug use in Australia: a wastewater analysis

Accurate information on drug use in communities is essential if health, social and economic harms associated with illicit drug use are to be addressed efficiently. In most countries population drug use is estimated indirectly via surveys, medical presentations and police and custom seizures. All of these methods have at least some problems due to bias, small samples and/or long time delays between collecting the information and analysing the results. Recently the direct quantification of drug residues in wastewater has shown promise as a means of monitoring drug use in defined geographical areas. In this study we measured 3,4-methylenedioxymethamphetamine (MDMA), methamphetamine and benzoylecgonine in sewage inflows in metropolitan and regional areas of Australia and compared these data with published European data. Cocaine use was small compared to European cities (p<0.001) but was compensated for by much greater consumption of methamphetamine (p<0.001) and MDMA (p<0.05). MDMA was more popular in regional areas (p<0.05) whereas methamphetamine and cocaine were mainly consumed in the city (p<0.05). Greater than 5-fold increases in MDMA use were detected on weekends (p<0.001). This approach has the potential to improve our understanding of drug use in populations and should be further developed to improve prevention and treatment programs.     

France,Britain and the intervention in Libya: an integrated analysis

This article seeks to explain the decisions by Nicolas Sarkozy's France and David Cameron's Britain to intervene in the 2011 Libyan crisis. None of the three major theories of international relations—constructivism, defensive realism and liberalism—can explain on its own such intervention decisions as the Libya case. The article's novel analytical model proposes that each theory emphasizes factors and mechanisms that explain part of the decision-making process and that these factors interact with state behaviour in complex ways. Britain and France initially began to consider intervention because they felt that the emergent norm of the ‘responsibility to protect’ applied to the Libyan case and because they believed the massive flows of refugees fleeing the violence were a threat to their border security. Both countries believed military intervention could be successful at relatively low cost and that if they did not intervene the problem would not be solved. At that point, the Sarkozy and Cameron governments engaged in initial action that made them more likely to intervene by jeopardizing their future economic relations with the Gaddafi regime and making him more likely to threaten them with future terrorist attacks. Taking initial action also meant that French and British prestige would ultimately have suffered had they not intervened to achieve a satisfactory solution to the crisis. Paris and London viewed international and regional support as a critical prerequisite for intervention and they sought and attained it. Finally, the Sarkozy and Cameron governments were able to minimize any domestic political risk of intervening because they had public and/or opposition party support.