The condition, which can cause erratic behavior and severe mental illness, is associated with repeated head trauma and has been found in hundreds of former NFL players in recent years.

This article was originally published on www.si.com as Doug Martin's Agent Issues Statement After Death of Former Buccaneers, Raiders RB. Former NFL running back Doug Martin died Sunday while in custody by the Oakland Police Department. He was 36.

Former NFL player Douglas Martin died while in police custody after an alleged "brief struggle occurred," says the Oakland Police Department.