In 2015, Norman Cooper, a 33-year-old unarmed black man, died at his parents home after being "tased" nine times by police officers. Now a medical expert says Cooper died not from his struggle with police but from a health condition called “excited delirium”—a controversial diagnosis that has divided the medical community but is still used by American medical examiners to account for hundreds of deaths in police custody. The Cooper family is suing the SAPD in a case that lawyers hope could help settle the battle over excited delirium.