Insights from a 6‐year hair drug analysis compendium in drug‐facilitated sexual assault cases

Drug-facilitated sexual assault (DFSA) may involve a diverse array of substances, including illicit drugs, prescription medications, and over-the-counter pharmaceuticals. Hair analysis has emerged as a valuable forensic tool, offering an extended window of detection spanning several months. However, interpreting drug concentrations in hair can be challenging in forensic cases, as there are still substantial disparities in drug concentration findings across studies, or even no data available in the literature. This compendium seeks to contribute to the understanding and interpretation of forensic cases involving hair analysis. This study included hair analysis results upon prosecutor request over 6 years in Grenoble Forensic Laboratory from 2019 to 2024. Segmental hair analysis was performed using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) on Sciex® 5500QT and Waters® TQ-XS mass spectrometers, following Society of Hair Testing guidelines. Screened substances included drugs of abuse, benzodiazepines, sedative medications, and gamma-hydroxybutyrate (GHB), depending on the case, following French Society of Analytical Toxicology guidelines. Hair proficiency quality testing ensured reproducible results. In this compendium, 22 authentic DFSA cases are described with hair analysis. The cohort predominantly involved female victims (95%) aged 13-47 years. Hair analysis was positive in nine cases (41%), revealing the presence of at least one psychoactive substance. Substances identified were alimemazine, alprazolam, bromazepam, cetirizine, clozapine, codeine, cyamemazine, hydroxyzine, oxazepam, zolpidem, and 3,4-methylenedioxymethamphetamine (MDMA). The chemical profile observed primarily included sedating and amnesic pharmaceuticals, but not only. This compendium adds valuable data in the literature for better hair drug concentration interpretation in forensic cases.