Investigative studies into the recovery of DNA from improvised explosive device containers

Apprehending those who utilize improvised explosive devices (IEDs) is a national priority owing to their use both domestically and abroad. IEDs are often concealed in bags, boxes, or backpacks to prevent their detection. Given this, the goal of the research presented was to identify IED handlers through postblast DNA recovery from IED containers. Study participants were asked to use backpacks for 11 days, after which they served as containers for pipe bombs. Eleven postdeflagration backpack regions likely to be handled were swabbed and analyzed via mini-short tandem repeats (miniSTRs) and alleles were called blind. An experimental consensus method was examined in which profiles from all regions were considered, to help identify spurious drop-in/out. Results were correct for all loci, except one that remained ambiguous. The results show that recovering DNA from IED containers is a viable approach for aiding in the identification of those who may have been involved in an IED event.     

Is Plea Bargaining in the “Shadow of the Trial” a Mirage?

It has been well established that a ??plea discount?? or ??trial penalty?? exists, such that defendants who plead guilty receive significant sentencing discounts relative to what they would receive if convicted at trial. Theorists argue that the exact value of this plea discount is determined by bargaining ??in the shadow of a trial,?? meaning that plea decision-making is premised on the perceived probable outcome of a trial. In trials, the strength of the evidence against defendants greatly impacts the probability of conviction. In the present study, we estimate the probability of conviction at the individual level for those who pled guilty. We find that, contrary to the shadow of the trial model, evidentiary factors either do not impact or negatively impact the probability of conviction, which stands in stark contrast to the impact evidence has at trials. These findings suggest that plea bargain decision-making may not occur in the shadow of the trial.     

Temporal Linkages in Violent and Nonviolent Criminal Activity

Research on the temporal distribution of criminal behavior has highlighted two distinct mechanisms—population heterogeneity and state dependence. Most of this work indicates that long-term patterns of criminal offending reflect a mixture of stable individual differences and the causal effect of life events and experiences. Yet several ambiguities remain. Among the most important of these problems is whether both population heterogeneity and state dependence processes operate for different types of offending. We use longitudinal official record and self-report data for violent and non-violent offending activity from the Rochester Youth Development Study to address these ambiguities.     

Using STR analysis to detect human DNA from exploded pipe bomb devices

This study investigated the possibility of recovering a bomb assembler's DNA from an exploded pipe bomb device. Metal and polyvinyl chloride (PVC) pipes were examined to determine if one surface type would allow better DNA recovery than the other. Ten subjects each handled components of one metal and one PVC pipe bomb. The bombs were exploded, the fragments were collected and swabbed using the double swab technique, and the samples were extracted, quantified, amplified, and genotyped using polymerase chain reaction/short tandem repeat (PCR/STR). Of the 20 bombs handled by the subjects, four bombs gave reportable results that matched the subject's known DNA profiles. An additional eight profiles, also matching the subject's known DNA profiles, were generated but were below the reportable threshold. There was no difference in the success rate of obtaining DNA profiles related to the use of either PVC or metal in the manufacture of the pipe bomb. The variables that appeared to have the greatest influence on the success of generating a DNA profile were the amount of fragmentation and subsequent recovery of the bomb fragments. It is suspected that successful DNA profiling could also be dependent upon the bomb assembler's propensity to slough skin cells on objects they handled.     

Personality and the Intergenerational Transmission of Educational Attainment: Evidence from Germany

Research based in the United States, with its relatively open educational system, has found that personality mediates the relationship between parents’ and child’s educational attainment and this mediational pattern is especially beneficial to students from less-educated households. Yet in highly structured, competitive educational systems, personality characteristics may not predict attainment or may be more or less consequential at different points in the educational career. We examine the salience of personality in the educational attainment process in the German educational system. Data come from a longitudinal sample of 682 17 to 25 year-olds (54% female) from the 2005 and 2015 German Socio-Economic Panel (SOEP). Results show that adolescent personality traits—openness, neuroticism, and conscientiousness—are associated with educational attainment, but personality plays a negligible role in the intergenerational transmission of education. Personality is influential before the decision about the type of secondary degree that a student will pursue (during adolescence). After that turning point, when students have entered different pathways through the system, personality is less salient. Cross-national comparisons in a life course framework broaden the scope of current research on non-cognitive skills and processes of socioeconomic attainment, alerting the analyst to the importance of both institutional structures and the changing importance of these skills at different points in the life course.     

Locking up my generation: Cohort differences in prison spells over the life course

Crime rates have dropped substantially in the United States, but incarceration rates have remained high. The standard explanation for the lasting trend in incarceration is that the policy choices from the 1980s and 1990s were part of a secular increase in punitiveness that has kept rates of incarceration high. Our study highlights a heretofore overlooked perspective: that the crime–punishment wave in the 1980s and 1990s created cohort differences in incarceration over the life course that changed the level of incarceration even decades after the wave. With individual-level longitudinal sentencing data from 1972 to 2016 in North Carolina, we show that cohort effects—the lingering impacts of having reached young adulthood at particular times in the history of crime and punishment—are at least as large (and likely much larger) than annual variation in incarceration rates attributable to period-specific events and proclivities. The birth cohorts that reach prime age of crime during the 1980s and 1990s crime–punishment wave have elevated rates of incarceration throughout their observed life course. The key mechanism for their elevated incarceration rates decades after the crime–punishment wave is the accumulation of extended criminal history under a sentencing structure that systematically escalates punishment for those with priors.