Hair testing for hypnotics in drug-facilitated sexual assault

Abstract

 Increasing numbers of drug-facilitated sexual assaults (DFSAs) have been reported recently and have become a social concern. In DFSAs, biological specimens (urine, blood, and hair) are analyzed to prove the victim's drug exposure, which can lead to proof of the sexual crime. Hair is the only specimen that can provide firm evidence of drug ingestion in cases of long delays (more than a week) in reporting the crime. Furthermore, detailed sectional hair analysis of a single hair strand enables to estimate the victim's drug-use history (date and amount of intake). Several recent studies have demonstrated high-sensitivity methods using mass spectrometry to detect sub-pg/mg concentrations of hypnotics in hair, and additionally illustrated the incorporation pathways of drugs and detailed distribution patterns in the hair after intake. Based on these findings, hair testing for hypnotics has been put to practical applications since 2016. In this paper, we review the practical concepts and usefulness of hair testing for hypnotics while introducing the current situation of DFSAs.