Shane Tamura speculated in a suicide note that he was suffering from CTE, a degenerative brain disease associated with sports-related head injuries

The 27-year-old man who shot and killed four people at a Midtown office building on Monday carried a note in his pocket, police sources told ABC News.

The gunman, Shane Tamura, may have suffered from chronic traumatic encephalopathy and played high school football in California.

The Nevada man behind a shooting spree in a Midtown Manhattan office building may have originally been targeting for the NFL headquarters, sources say.

Law enforcement sources say a three-page note Shane Tamura was carrying included references to the NFL and a former player diagnosed with CTE.

The mother of the man who killed four people at a Manhattan office tower home to the NFL told 911 dispatchers during a 2022 incident when he threatened to kill himself that he suffered from a sports-r

The mother of the man who killed four people at a Manhattan office tower home to the NFL before taking his own life told 911 dispatchers during a 2022 incident when he threatened to kill himself that he suffered from a sports-related concussion and other issues,