Identification and Comparison of Electrical Tapes Using Instrumental and Statistical Techniques: II. Organic Composition of the Tape Backing and Adhesive*

Abstract: The microtexture and elemental composition of the backing of electrical tapes have been shown to be highly discriminating. In this study, the organic composition of electrical tape was evaluated as a complementary means of distinguishing tape brands. The backing and adhesive of 72 rolls of electrical tape were analyzed via Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR FTIR) and discriminant analysis was used to classify all samples by brand. Generally, the accuracy for FTIR data (88–99%) was higher than that for elemental data (86–94%). FTIR spectra from the adhesive layer were the most discriminating. In separate studies, two fragments of blast-damaged tape were correctly assigned to their brand of origin and discriminant analysis was used to quantitatively associate or exclude tape samples from two bombing cases.     

Effects of administrative ignition interlock license restrictions on drivers with multiple alcohol offenses

This study investigated, under real-world conditions, whether a statewide 2-year administrative ignition interlock license restriction program in Maryland was effective in reducing subsequent alcohol-related traffic violations among multiple offenders and whether any reductions in recidivism could be maintained after the program ended and interlock license restrictions were removed. A total of 1,927 drivers eligible for relicensure were randomly assigned to either the 2-year interlock license restriction program or the normal and customary sanctions afforded multiple offenders in Maryland. Recidivism was defined as incurring a subsequent alcohol-impaired driving violation during the 2-year intervention or 2-year postintervention periods. Compared to the control group, participation in the interlock license restriction program reduced drivers’ hazard (or risk) of a subsequent alcohol-impaired driving offense by a statistically significant 36% during the 2-year intervention, 26% during the 2-year postintervention period, and 32% during the entire 4-year study period. This investigation of interlock program effectiveness is the first to report significantly lower recidivism among the interlock group than its control group after the ignition interlock license restriction program ended. Possible reasons for this novel finding and areas for future research are discussed.     

Forensic identification of urine using the DMAC test: a method validation study

Forensic scientists may sometimes be asked to identify the presence of urine in cases such as harassment, rape or murder. One popular presumptive test method uses para-dimethylaminocinnamaldehyde (DMAC), favoured because it is simple, rapid and safe. This paper confirms that DMAC reacts with urea rather than creatinine, ammonia or uric acid. Sensitivity studies found that the 0.1% w/v DMAC solution currently used for urine identification detects levels of urea found in other body fluids, potentially resulting in false positives. A 0.05% w/v solution was found to be more appropriate in terms of sensitivity to urea however the test is still not specific for urine, giving positive reactions with a number of body fluids (saliva, semen, sweat and vaginal material) and other substances (foot lotion, hair removal cream and broccoli).     

The impact of race and extra-legal factors in charging defendants with serious sexual assault: Findings from a five-year study of one Pennsylvania court jurisdiction

Research on sexual assault case processing remains mixed regarding how extra-legal factors such as the racial-ethnic composition of the defendant-victim dyad may impact prosecutorial decision-making. We use data from 2006–2010 in a Pennsylvania county court jurisdiction to examine the victim- and defendant-related factors that influence charging decisions. We also explore how the demographic and offense characteristics influence decisions to prosecute offenders for more serious types of sexual assault. Our findings indicate that the racial composition of the defendant-victim dyad contributed to the prosecutorial decision to charge an offender with a more serious sexual assault, while victim characteristics and use of violence during the offense were not related to seriousness of the charge.