was used. >> narrator: the night before ware's encounter at the rest stop, an unarmed man named elijah mcclainained by police in aurora, colorado. the officers called for paramedics, who injected mcclain with ketamine. he went into cardiac arrest and died a few days later. >> elijah mcclain's case was a stepping-off point where we began to take a harder look at other deaths. and what we discovered was troubling. we discovered there were many other cases where the combination of prone restraint and chemical sedation had resulted in death. >> narrator: colorado placed significant restrictions on the use of ketamine in the field, including banning police officers from directing paramedics to administer the sedative. >> narrator: one officer involved in mcclain's death was convicted of criminally negligent homicide and third-gree assault. two others were acquitted. in a rare homicide prosecution of medical personnel, the two paramedics who'd injected mcclain with ketamine were also found guilty. dr. roger mitchell was an expert witness in the trials. >> every excited delirium case in this country