A Comparison of Cleaning Regimes for the Effective Removal of Fingerprint Deposits from Brass

Abstract:  Effective removal of fingerprint deposits is crucial for experimentation related to the corrosion of metals by fingerprint deposits. Such removal is also necessary prior to deposition of test fingerprints. The effectiveness of four regimes in removing fingerprint deposits from brass is considered. Sustained wiping of the deposit with a tissue at applied pressures of up to c . 1430 Pa or rubbing while the brass was immersed in acetone both failed to remove completely all traces of fingerprint deposits. Heating the brass to 600°C was an effective remover; however, this also oxidized the surface of the metal except where inhibited by fingerprint deposits. The most effective regime, and the only one of the four that removed all traces of deposit without affecting the properties of the metal surface, was immersion in warm soapy water while rubbing with a tissue. We propose this as the preferred method for fingerprint removal.     

A Statistical Validation of the Individuality and Repeatability of Striated Tool Marks: Screwdrivers and Tongue and Groove Pliers*

Abstract: Tool mark identification relies on the premise that microscopic imperfections on a tool’s working surface are sufficiently unique and faithfully transferred to enable a one‐to‐one association between a tool and the tool marks it creates. This paper presents a study undertaken to assess the validity of this premise. As part of this study sets of striated tool marks were created under different conditions and on different media. The topography of these tool marks was acquired and the degree of similarity between them was quantified using well‐defined metrics. An analysis of the resulting matching and nonmatching similarity distributions shows nearly error‐free identification under most conditions. These results provide substantial support for the validity of the premise of tool mark identification. Because the approach taken in this study relies on a quantifiable similarity metric, the results have greater repeatability and objectivity than those obtained using less precise measures of similarity.     

Quick Screening of Crystal Methamphetamine/Methyl Sulfone Exhibits by Raman Spectroscopy

Abstract: The analysis of mixtures of “crystal meth” (usually comprised of methyl sulfone [MS] and methamphetamine [MA]) by gas chromatography‐mass spectrometry (GCMS) is routine in many forensic drug laboratories. The utilization of Raman spectroscopy for the identification of such mixtures quickly and without the need for a separation technique is discussed. Samples were dissolved in water and Raman spectra of the resulting aqueous solutions were collected. By comparing these spectra to spectra of methylsulfone and MA mixtures of known composition, an indication of the composition of the sample can be obtained in only a few minutes. This spectral comparison also can be used as a semi‐quantitative analysis of MA concentrations in such exhibits.     

Root Morphology and Anatomical Patterns in Forensic Dental Identification: A Comparison of Computer‐Aided Identification with Traditional Forensic Dental Identification*

Abstract: An online forensic dental identification exercise was conducted involving 24 antemortem–postmortem (AM–PM) dental radiograph pairs from actual forensic identification cases. Images had been digitally cropped to remove coronal tooth structure and dental restorations. Volunteer forensic odontologists were passively recruited to compare the AM–PM dental radiographs online and conclude identification status using the guidelines for identification from the American Board of Forensic Odontology. The mean accuracy rate for identification was 86.0% (standard deviation 9.2%). The same radiograph pairs were compared using a digital imaging software algorithm, which generated a normalized coefficient of similarity for each pair. Twenty of the radiograph pairs generated a mean accuracy of 85.0%. Four of the pairs could not be used to generate a coefficient of similarity. Receiver operator curve and area under the curve statistical analysis confirmed good discrimination abilities of both methods (online exercise = 0.978; UT‐ID index = 0.923) and Spearman’s rank correlation coefficient analysis (0.683) indicated good correlation between the results of both methods. Computer‐aided dental identification allows for an objective comparison of AM–PM radiographs and can be a useful tool to support a forensic dental identification conclusion.     

Validation of an LC–MS Method for the Detection and Quantification of BZP and TFMPP and their Hydroxylated Metabolites in Human Plasma and its Application to the Pharmacokinetic Study of TFMPP in Humans*

Abstract: An LC–MS method was developed for benzylpiperazine (BZP) and trifluoromethylphenylpiperazine (TFMPP), constituents of “party pills” or “legal herbal highs,” and their metabolites in human blood plasma. Compounds were resolved using a mixture of ammonium formate (pH 4.5, 0.01 M) and acetonitrile (flow rate of 1.0 mL/min) with a C18 column. Calibration curves were linear from 1 to 50 ng/mL (R² > 0.99); the lower limit of quantification (LLOQ) was 5 ng/mL; the accuracy was >90%; the intra‐ and interday relative standard deviations (R.S.D) were <5% and <10%, respectively. Human plasma concentrations of TFMPP were measured in blood samples taken from healthy adults (n = 6) over 24 h following a 60‐mg oral dose of TFMPP: these peaked at 24.10 ng/mL (±1.8 ng/mL) (C_max) after 90 min (T_max). Plasma concentrations of 1‐(3‐trifluoromethyl‐4‐hydroxyphenyl) piperazine peaked at 20.2 ng/mL (±4.6 ng/mL) after 90 min. TFMPP had two disposition phases (t_½ = 2.04 h (±0.19 h) and 5.95 h (±1.63 h). Apparent clearance (Cl/F) was 384 L/h (±45 L/h).     

Criminal career progression among serious youthful offenders in Australia

An important question from research on criminal careers is whether the processes that generate participation in criminal activity are similar to those that drive offending frequency among those who have initiated. This article considers basic demographic correlates asking whether those factors are associated with both initial and sustained early adulthood criminality in Australia. Three findings emerged from the study: (1) the offenders exhibited high levels of criminal activity during early adulthood; (2) males were more likely than females to offend and offend at higher rates as adults; and (3) Indigenous youth were more likely than non-Indigenous youth to offend and offend at higher rates as adults. Overall, the study results showed that basic correlates of crime were linked to both participation and frequency of offending in early adulthood—even within a sample of serious offenders. The article addresses the theoretical implications of the findings and directions for future research.     

Informal Controls and the Explanation of Propensity to Offend: A Test in Two Urban Samples

Propensity to offend is an important and stable predictor of offending. A person’s propensity is often thought of as a multidimensional trait consisting of morality and low self-control. The aim of this paper is to explain individual differences in propensity to offend as one single construct and two of its dimensions, namely morality and low self-control. It is well established that low levels of morality and low self-control increase the risk of offending. However, there is less empirical research that focuses on the main predictors of morality and self-control. Therefore the main research question for this study is to explain to what extent parental attachment, parental control and the school social bond have a direct effect on one’s propensity to offend (low morality or delinquency tolerance and low self-control). The data are drawn from two different samples of young adolescents in Antwerp, Belgium (N = 2,486), and Halmstad, Sweden (N = 1,003). The results show that parental control, parental attachment and the school social bond have direct effects on individual differences in propensity to offend, regardless of individual background variables. The results are highly equivalent in both samples. The similarity of the results across two independent samples suggests that the findings are stable. Implications for further studies are discussed.     

Exploring gender differences in dating violence/harassment prevention programming in middle schools: results from a randomized experiment

In this study, we randomly assigned 123 sixth and seventh grade classrooms from seven middle schools in the greater Cleveland area to one of two five-session curricula addressing gender violence/sexual harassment (GV/SH) or to a no-treatment control group. A baseline survey and two follow-up surveys were administered immediately after the treatment (Wave 2) and about six months post-treatment (Wave 3). In an earlier paper, we demonstrated the effectiveness of two approaches to youth GV/SH prevention programming (a fact-based, law and justice curriculum and an interaction-based curriculum). In this paper, we explored whether these largely positive findings remain for both girls and boys, including whether girls experience higher levels of GV/SH than boys. Most of our statistical models proved to be non-statistically significant. However, in 2 of our 48 victimization/perpetration (any violence, sexual violence and non-sexual violence) models (across two post-intervention follow-up points), we observed that the interventions reduced peer (male or female, non-dating partner) sexual violence victimization and reduced peer perpetration, but another outcome model indicated that the interventions increased dating perpetration. These mixed findings will need to be explored further in future research. Regarding our primary research question, we observed no statistically significant differences for the treatment multiplied by gender interaction terms for any of the perpetration or victimization outcome models, suggesting that the treatment had similar effects on girls and boys. However, we did observe that boys are more involved in violence than girls: both as victims and perpetrators. Boys experienced significantly more of three types of victimization from peers and dating partners compared to what girls experienced at the hands of their peers and dating partners. As perpetrators, boys committed more sexual victimization against peers (immediately post-intervention only) and more sexual victimization against dating partners than girls. The implications of these results are discussed.     

Toward a Typology of High-Risk Major Stressful Events and Situations in Posttraumatic Stress Disorder and Related Psychopathology

The diagnosis of posttraumatic stress disorder (PTSD) was introduced in 1980 with the publication of the Diagnostic and Statistical Manual of the American Psychiatric Association, Third Edition (DSM-III). DSM-III put forward a novel syndrome consisting of intrusive, avoidance/numbing, and arousal symptoms as distinctive psychopathology following exposure to traumatic events. The traumatic stressors, although expanded in later editions published in 1987 (DSM-III-R) and 1994 (DSM-IV), focus on life-threatening events and situations. However, at least 12 studies, most of them recent, have found associations between the PTSD symptoms and the PTSD symptom syndrome with stressors, such as unemployment and divorce that would not qualify, even in the broadened DSM-IV diagnosis, as traumatic stressors. These findings challenge the basic assumption on which the PTSD diagnosis is based, the assumption that exposure to life-threatening stressors is the primary cause of a unique set of stress response symptoms. The purpose of this paper is to show how to confront this challenge by developing a typology of stressful situations and events that can be tested systematically for their relation to the PTSD symptom syndrome and other relevant variables. The typology includes but is not limited to the types of situations and events defined as "traumatic" in the DSMs.