The NYC mass shooter blamed football for his actions. But Dr. Bennet Omalu, the man who discovered CTE, says that excuse doesn’t hold up.

Shane Tamura, the Park Ave. gunman who killed an NYPD officer and three others before taking his own life, left behind a suicide note saying he suffered from CTE, a brain injury often linked to playing football, and was targeting the NFL — but took the wrong elevator, officials said Tuesday.

Researchers have diagnosed many former football players with CTE since 2005. It can only be diagnosed through a brain autopsy after the patient dies.