Dual one-step LC-MS/MS methods for hair analysis in drug-facilitated crime: application to an alleged Fraud-Related...

This study aimed to develop and validate two simplified, one-step extraction methods coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the simultaneous segmental analysis of psychoactive substances, specifically doxylamine (DOX), haloperidol (HAL), citalopram (CTP), sildenafil (SDF), and common illicit drugs in hair samples. A secondary objective was to apply these methods to a real-life forensic case involving suspected prolonged drug-facilitated crime (DFC) with suspected non-consensual exposure with financial implications.Two analytical methods based on one-step extraction protocols coupled with LC-MS/MS were developed and validated according to ANSI/ASB 036 standards. One method was based on ultrasonic solvent extraction (USE), while the other relied on passive solvent incubation (PSI). Hair samples from two victims were collected and segmented to assess chronic drug exposure. Analytical performance was evaluated in terms of linearity, sensitivity, accuracy, precision, matrix effects, recovery, and dilution integrity.Both methods demonstrated high sensitivity (LODs as low as 0.27 pg/mg), accuracy (bias within ± 15%), and precision (RSD ≤ 18.3%). Segmental analysis of Victim A's hair revealed DOX and HAL concentrations consistent with chronic, non-consensual administration. HAL was also detected in Victim B's scalp and leg hair, while DOX was absent. The segmental distribution patterns supported the hypothesis of prolonged sedative non-consensual drug exposure.This study presented a rare case of drug-facilitated crime involving chronic administration of HAL and DOX within an alleged deception-based context. The validated LC-MS/MS methods proved to be robust, cost-effective, and suitable for routine forensic toxicology. Segmental hair analysis provided critical retrospective evidence, reinforcing its value in complex DFC investigations. The interpretation remained confined to analytical evidence, without inferring intent.