Legal issues associated with PCP abuse--the role of the forensic expert.

These cases illustrate some of the complex issues associated with PCP-related litigation. The concept that malice is implied when an experienced drug user commits a crime while under the influence of the drug is not held in most states, at the present time. The authors have now reviewed in detail four cases of unexpected death following the use of neck holds in PCP-intoxicated individuals. In all of the cases, multiple carotid compression holds had been attempted, according to the history. Skin abrasions, hemorrhage into the soft tissues of the neck, and fractures of the hyoid bone and thyroid cartilage provide structural evidence of the application of substantial force to the neck. On autopsy, there has been no evidence of lethal injuries to the bronchial tree, brain, or heart. Drugs related to PCP are known to alter the carotid sinus reflex. Mechanical stimulation of the carotid sinus in the neck normally results in a slowing of heart rate and a decrease in blood pressure. Carotid sinus stimulation, coupled with the effects of PCP on blood vessels, might result in a marked fall in the blood pressure that could lead, ultimately, to death. Individuals intoxicated with PCP may be at a higher risk to complications of carotid compression neck holds. Hence, additional cases would be expected to become medicolegal issues.