Transfer and Distribution of Gunshot Residue through Glass Windows

Research into the deposition patterns of primer gunshot residue (GSR) beyond a primary target was previously nonexistent. This study aimed to determine the deposition patterns of GSR once a bullet passed through an initial target and continued on its path into additional targets. Multiple repetitions were performed to assess the GSR deposition patterns after a bullet was shot through a closed window into either a dummy or a wall within an enclosed room. Samples were taken from both the primary and secondary target holes as well as from nontarget areas. Significant amounts of GSR were found on all samples. The results show that GSR continues to be deposited along the path of the bullet after passing through a primary glass target. These findings reiterate the lack of probative value in collecting GSR samples from gunshot victims even if they are in an enclosed area separate from the shooter.     

Modeling Change in Perceptions about Sanction Threats: The Neglected Linkage in Deterrence Theory

Deterrence theory describes a process of offender decision making that consists of two linkages—one in which official sanctions and other information affect a would-be offenders perceptions about the risks of criminal conduct, and another in which such perceptions influence the decision whether or not to offend. Decades worth of empirical research has concentrated virtually exclusively on this latter linkage, and in so doing, has produced an incomplete account of the deterrence process. This article develops a model of how perceptions of sanction certainty are modified in response to an individuals involvement in criminal activity and the consequences (if any) therefrom. Implications of the model are tested with data from a multi-wave, panel survey of 1,530 high school students from the southeastern U.S. Key findings include: the manner in which new information affects perceived certainty depends on the level of perceived certainty before the new information is received, and the extent of peer offending was one of the most influential factors in determining change in perceived sanction certainty over time.     

The effect of economic events on votes for president: 1984 update

In previous work I have developed an equation explaining votes for president in the United States that seems to have remarkable explanatory power. In this paper the equation is updated through the 1984 election and then used to predict the 1988 election.     

The analysis of an intracerebral hematoma for drugs of abuse

Toxicological investigations were performed on an intracerebral hematoma, antemortem blood, and postmortem blood of an individual who was found unresponsive in his home. The hematoma was found to have ethanol at a concentration of 0.05% (w/v), and benzoylecgonine (a cocaine metabolite) was also confirmed at a concentration of 0.43 mg/L by specific analysis using gas chromatography/mass spectrometry (GC/MS). These results enabled the pathologist to record the cause of death as intracerebral hemorrhage due to acute cocaine intoxication.     

Inference of human geographic origins using Alu insertion polymorphisms

The inference of an individual's geographic ancestry or origin can be critical in narrowing the field of potential suspects in a criminal investigation. Most current technologies rely on single nucleotide polymorphism (SNP) genotypes to accomplish this task. However, SNPs can introduce homoplasy into an analysis since they can be identical-by-state. We introduce the use of insertion polymorphisms based on short interspersed elements (SINEs) as a potential alternative to SNPs. SINE polymorphisms are identical-by-descent, essentially homoplasy-free, and inexpensive to genotype using a variety of approaches. Herein, we present results of a blind study using 100 Alu insertion polymorphisms to infer the geographic ancestry of 18 unknown individuals from a variety of geographic locations. Using a Structure analysis of the Alu insertion polymorphism-based genotypes, we were able to correctly infer the geographic affiliation of all 18 unknown human individuals with high levels of confidence. This technique to infer the geographic affiliation of unknown human DNA samples will be a useful tool in forensic genomics.