Crimes involving the use of veterinary anesthetics on humans occur occasionally, but the cases involving xylazine and haloperidol are rarely reported. In forensic practice, there are still no specific postmortem signs, lack of histopathological changes with absolute diagnostic value, and no recognized toxic and lethal blood concentrations of xylazine and haloperidol for humans, which make it difficult to identify poisoning or death induced by xylazine and haloperidol. This paper analyzes a case in which two people were killed by injection of a veterinary anesthetic compound preparation combined with other methods. It summarizes experiences, practices, and key considerations in handling poisoning cases, focusing on case details, scene examination, clothing inspection, autopsy, and collection of toxicological samples. It particularly emphasizes the importance of conducting standardized and systematic autopsies in such cases to ensure that the forensic findings and conclusions are complete, accurate, and comprehensive. This paper presents the concentrations of xylazine and haloperidol in the blood and tissues of the two deceased, providing reference data for forensic research and practice.