The gunman who had suspected he had CTE when he shot several people in a Manhattan office building did in fact have the disease, the New York City medical examiner said Friday.

The shooter, Shane Devon Tamura, 27, who played high school football, shot and killed himself after fatally shooting four people in July. The medical examiner said he had “unambiguous diagnostic evidence” of low-stage CTE, or chronic traumatic encephalopathy.