Homicidal poisoning series in a nursing home: retrospective toxicological investigations in bone marrow and hair

AbstractHomicidal poisonings remain rare and can be difficult to detect, especially in the elderly or in medical settings. In this atypical poisoning series, a young nursing assistant purposely poisoned thirteen residents of a nursing home and killed ten of them. The medications used were a mix of psychotropic medications (cyamemazine, loxapine, tiapride, risperidone, and mirtazapine), under liquid formulation, which were inducing malaise and coma. The forensic investigation included analysis of blood, urine, hair, and bone marrow and exhumations of seven corpses up to 3  years after the inhumation. Hair collected from a hairbrush of a cremated victim have been analyzed. Bone marrow sample preparation was based on a liquid/liquid triple extraction. Hair were incubated after decontamination overnight at 55 °C in methanol. Segmentation was possible for seven sample s, except for delayed exhumation samples (n = 4) and hairbrush hair sample (n = 1). The extracts were then analyzed using gas chromatography coupled with mass spectrometry (GC–MS) for unknown screening and using liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS) for a targeted screening and quantification. Screenings revealed the presence of the s ame mix of psychotropic medications. Cyamemazine, mirtazapine, loxapine, tiapride, and risperidone hair concentrations were 6–17,458 pg/mg, 74–1271 pg/mg, 9–1346 pg/mg, 13–148 pg/mg, and 3–5 pg/mg, respectively. Cyamemazine ...
Source: International Journal of Legal Medicine - Category: Medical Law Source Type: research