Police have identified the man who they say entered a Midtown Manhattan office building wearing body armor and opened fire, killing four people with a high-powered rifle, as Shane Devon Tamura.

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.