The coroner office’s autopsy report, updated in 2021, found that McClain died of an overdose of ketamine that was given after he was forcibly restrained by police. While it found no evidence that the police actions contributed to McClain’s death, prosecutors presented their own medical expert who said there was a direct link. Dr. Roger Mitchell of Howard University, the former Washington, D.C. coroner, said the police restraint caused a series of cascading health problems, including difficulty breathing and a buildup of acid in McClain’s body.