In a video message, Tisch said Tamura left a suicide note and claimed to be suffering from chronic traumatic encephalopathy (CTE), possibly from playing high school football. Tamura also blamed the NFL and asked that his brain be studied for signs of the degenerative disease.

Wearing body armor and wielding an assault-style rifle, the alleged gunman burst into a Midtown Manhattan office building shooting victims at random.

The gunman, who said in a note he believed he had CTE, targeted skyscraper that houses the NFL's headquarters.