Shane Tamura — who fatally shot four people at a Midtown East office building — said in a suicide note he believed he suffered from CTE and requested his brain be studied.

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.

Shane Tamura, a 27-year-old former high school football player from Las Vegas with a documented mental health history, was identified as the gunman who killed four people, including an NYPD officer, in a mass shooting at 345 Park Avenue in Manhattan on July 28,