Evaluation of suspected drug-facilitated sexual assault cases in the city of Houston from 2014 to 2020.

Drug-facilitated sexual assault is a form of sexual violence against an individual incapacitated by alcohol and/or drugs consumed voluntarily or covertly administered. The purpose of this study was to evaluate toxicological results and the associated demographics of sexual assault-related cases submitted to Houston Forensic Science Center from 2014 to 2020. In total, 1240 samples (1230 cases) were tested during the six-year period that consisted of blood, urine, or both specimens. Blood was analyzed for ethanol by dual-column headspace gas chromatography with flame ionization detection. Drug screen analysis was performed preferably on urine specimens using enzyme-linked immunosorbent assay. Positive screening results were confirmed upon request only due to laboratory policy. A total of 22% (n = 176) of requested samples were confirmed positive. Ethanol was the most prevalent substance detected, present in 17% of the samples (n = 212), followed by 11-nor-9-carboxy-delta-9-tetrahydrocannabinol (THC-COOH) (n = 118). The combination of ethanol and THC-COOH was the most frequent one found (n = 17) in cases positive for two or more drugs (n = 101). Demographic data showed the majority of DFSA victims were white (25%) females (72%) with an average age of 27 years old (n = 348). Almost 90% of cases where the presence of drugs was confirmed resulted in no charges being made, either due to lack of suspect information or unknown reasons by the laboratory.

Recovery of oxygenated ignitable liquids by zeolites, Part II: Dual-mode heated passive headspace extraction.

Previous studies performed by our research group have suggested that zeolites are a suitable adsorbent for the recovery of oxygenates from fire debris through heated passive headspace extraction. Zeolite 13X, in particular, has been shown to be effective for recovering analytes with molecular diameters smaller than 10Å. The primary aim of this study was to evaluate the addition of zeolite 13X to heated headspace extraction for the recovery of ignitable liquids. Comparative recoveries of petroleum and alcohol-based ignitable liquid mixtures were studied utilizing activated charcoal strips and zeolites, individually and in tandem. In the presence of both adsorption media within the same sample can, activated charcoal strips recovered the majority of gasoline components, while zeolites recovered the majority of oxygenated compounds. This phenomenon was attributed to the size exclusion properties, polarity, and available surface area of zeolites. This research supports the use of zeolites with activated charcoal strips in a "dual-mode" preparation for casework in which the presence of an ignitable liquid is suspected. The described method allows for the recovery and concentration of ignitable liquid residues in a single extraction procedure, whether the ignitable liquid is petroleum-based or oxygenated in nature.