Chloralose analysis in a criminal case

Abstract

To present, in a murder case, toxicological findings of chloralose in non-biological and biological matrices including hair. A 28-year-old woman was found dead in her bedroom. The same morning her former flatmate, worried because she had had no news from her friend, went to the victim's home where she was met by a male friend of the victim who forced her to drink a paste-like, bitter liquid at knifepoint. After ingestion, she immediately felt very tired and almost incapable of moving. She eventually managed to escape from the flat. The suspect was arrested some days later. He admitted strangling the deceased victim and trying to kill himself with a type of rat poison called Caussade ® . To our knowledge, this company only sells two products on the French market: chloralose and brodifacoum. The autopsy confirmed cause of death by strangulation associated with massive bronchial inhalation of vomit. The judge ordered a toxicological investigation of blood, urine and hair (collected 3 months after the murder) from the surviving victim (former flatmate), hair from the perpetrator (taken 6 weeks after his arrest), autopsy samples from the deceased victim and various different materials that were collected at the scene (powder, liquid, a cup and drinking glasses). Hair strands were decontaminated twice and then segmented as appropriate to cover the period of interest. Each segment of hair was cut into small pieces (< 1 mm) followed by a liquid-liquid extraction process and analysed by LC-MS/MS. Biological fluids and collected materials were submitted for GC-MS, LC-DAD and LC-MS/MS analysis. Specific investigations focused on chloralose and brodifacoum. The analyses show the following main results ( Table 1 ). Toxicological analysis confirmed that the rodenticide poison used by the perpetrator to try and commit suicide and to poison both victims was composed exclusively of chloralose. In particular, hair analysis for chloralose (for which there is very limited data within the scientific literature), allowed us to unequivocally confirm the perpetrator's statements and provide useful input to the police investigation. The symptoms observed in the surviving victim are in accordance with an oral absorption of chloralose. Concerning the deceased victim, the concentrations of chloralose measured were much lower than those encountered in other non-fatal and fatal poisoning cases, for which postmortem blood concentrations from 5 to over 100 μg/mL have been observed. Despite the probable low exposure to this pesticide and given that the main cause of death is known, the potential contributory role of chloralose, which can cause vomiting and lead to bronchial inhalation, cannot be totally ruled out.