The evaluation of the extent of transporting or "tracking" an identifiable ignitable liquid (gasoline) throughout fire scenes during the investigative process

Tests have determined that boots or shoes of individuals at a fire scene do not transport sufficient contaminants ("tracking") through the fire scene to produce a positive laboratory result for the presence of gasoline in a fire scene that was not present at the time of the fire. Questions about the validity of forensic laboratory results have been raised on the basis that low-level gasoline residues detected in the laboratory samples could have been the result of transporting the residue by footwear contaminated from the fire scene ("tracking"). The data collected in this study establish that "tracking" does not lead to false-positive laboratory results. Canines trained and experienced in the detection of trace ignitable liquid residues were also utilized in this study. The canine results confirmed that properly trained canines show a higher sensitivity than do standard ASTM laboratory techniques for fire debris analysis. In a few cases, canines responded to contamination, but laboratory testing (which is the definitive indicator) did not produce positive results.     

Differentiation of black gel inks using optical and chemical techniques

Gel ink pens have become a common writing instrument in the United States. Questioned document examiners often attempt to optically differentiate gel inks from each other and from other non-ballpoint ink writings (e.g., those from roller-ball pens). Since early formulations were primarily pigment-based, they do not elute when analyzed by thin-layer chromatography. However, recent gel ink formulations (i.e., within the past five years) include dye-based inks that can be easily separated. This study differentiates black gel inks using optical and chemical techniques. The techniques include: microscopy, visible and near infrared reflectance, near infrared luminescence, thin-layer chromatography (TLC), spot tests, and gas chromatography/mass spectrometry (GC/MS). As a result of this study a flow chart has been developed allowing for a systematic determination of a questioned ink. In addition, an analysis of volatile compounds found in gel inks revealed that there are some unique ingredients that may be found in gel inks that are not typically found in other non-ballpoint inks.     

The forensic analysis of thermal transfer printing

Thermal transfer printing refers to printing processes that utilize heat to produce an image by either physical or chemical means or by a combination of both. As the technology has improved and the supplies have become less expensive, the use of thermal printing in the personal and business markets has increased significantly. Specifically, dye diffusion thermal transfer and thermal mass transfer have become predominant in the production of counterfeit credit cards, drivers' licenses, and other types of documents produced on plastic media. Chemical analysis by means of thin layer chromatography (TLC) has proven to be useful in characterizing various types of inks (e.g., writing and inkjet inks). In this study, the authors examined 81 different samples that included a total of 54 printer samples (43 photographic prints on paper and eleven plastic card samples) and 27 printer ribbons. A new TLC method was developed and tested utilizing a solvent system (80% n-hexane, 3% methyl ethyl ketone, and 17% ethyl acetate) that is capable of producing excellent resolution.     

Identifying sex chromosome abnormalities in forensic DNA testing using amelogenin and sex chromosome short tandem repeats

Forensic DNA laboratories worldwide have begun using multiplexed STR systems to decrease analysis time and increase sample throughput. The loci used in these systems are basically "nonsense" regions of human DNA. However, due to the chromosome on which some of these loci are located, various genetic abnormalities can sometimes be detected. This paper will show one such abnormality--Klinefelter's Syndrome--and the process used to show the possibility of this defect in two undiagnosed males using peak height ratios at the Amelogenin locus, and X-Y STRs.     

Use of the MMPI-2 and the Inwald personality inventory to identify the personality characteristics of dropouts from a state police academy

The MMPI-2 and the Inwald Personality Inventory were employed to investigate the personality characteristics of dropouts from a state police academy. A traditional model of training borrowed from military models was used at the academy rather than a police generated model. Sensitive and independent individuals, more compatible with modern community policing methods may have rejected police work as a result of the experience. 15 academy completers and 9 dropouts were used in the sample. Analyses of the scales of the MMPI-2 and the Inwald Personality Inventory identified variables upon which the two groups differed. The hypothesis that more sensitive, empathic and independent individuals were leaving the academy appeared to be supported.     

Substance abuse minimization: Conceptualizing prevention in adolescent and youth programs

This article provides an overview of the historical and theoretical work on adolescent substance abuse with implications for preventive interventions. The focus is on an illustration of the use of four basic prevention tools: education, competency promotion, community mobilization, and natural care giving.Research interests include mental health, family relations, adolescence, and primary prevention.Research interests include family and social relations, adolescent personality social development.     

Why do people vote? An experiment in rationality

The study presents the findings of an experiment conducted during the 1993 Canadian fedeal election campaign. Students in two universities were exposed to a ten-minute presentation about the rational model of voting and the ‘paradox’ that so many people vote when it is apparently irrational on a cost-benefit basis. Our data indicate that exposure to the presentation decreased turnout in the election by seven percentage points. This result contributes to the debate abut the effect of rational-choice models on real political behavior. More important, the experimental panel data permit the presentation's effect to be decomposed, and this helps explain why people do vote. In this study, turnout was reduced mainly because the presentation diminished the respondents' sense of duty, an effect that was indirect, because there was no reference in the presentation to such motives. Framing the voting act in rational-choice terms induced some students to reconsider whether they should feel obliged to vote.     

Prescriptive and Elicitive Approaches to Conflict Resolution: Examples from Papua New Guinea

Negotiation Journal -