Tamura was involuntarily held after being considered a danger to himself or others, according to a law-enforcement official.

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, police sources said Tuesday.

Compared to what’s on the news, I don’t think any one of us, none of my teammates, sensed anything like this from Shane,” the former teammate told The Post.

New York City Mayor Eric Adams said on "Morning Joe" on MSNBC there is belief Tamura may have been targeting the NFL office in the building.