Gunman Shane Tamura had a ‘documented mental health history’ and ‘sprayed’ the Manhattan office building lobby with a military-style assault rifle, police say

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

The Palmetto State Armory AR-15 assault rifle used in the shooting that killed an NYPD cop and four civilians is .223-caliber and is equipped with a black scope, a handguard and a shoulder sling.

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.

In 2022, Nevada enacted a ban on ghost guns, which are firearms without serial numbers that are sold as kits that users assemble on their own. It is one of 15 states that created legislation regulating those weapons, which law enforcement has flagged as untraceable.

"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.

No motive has been announced. A suicide note was found expressing grievances with the NFL and saying Tamura suffered from CTE, a source said. Follow for live updates.

Shane Tamura, who shot and killed four people in a Manhattan office building, once worked surveillance for a Las Vegas casino. In a suicide note, the 27-year-old referenced CTE and claimed the NFL "failed" him.