Sports / CTE Aaron Hernandez Had CTE Brain exam finds he had stage 3 chronic traumatic encephalopathy By Evann Gastaldo, Newser Staff Posted Sep 21, 2017 4:39 PM CDT Copied In this April 11, 2017, file photo, defendant Aaron Hernandez listens as Judge Jeffrey Locke addresses the jury's question during his double murder trial at Suffolk Superior Court in Boston. (AP Photo/Elise Amendola, Pool, File) Former NFL player Aaron Hernandez was suffering from "severe" CTE when he killed himself, according to a postmortem brain exam conducted at Boston University, Sports Illustrated reports. Chronic traumatic encephalopathy, which is caused by repeated blows to the head and frequently affects football players and other athletes, can only be diagnosed after death. Hernandez had stage 3 CTE; there are four total stages of the degenerative disease and SI notes that it has been associated with "a propensity for violence." Hernandez was convicted of murder before his suicide. (More CTE stories.) Report an error