Shame Tamura, the gunman who opened fire inside 345 Park Ave. on Monday evening, had a lengthy history of mental health issues, officials said at a press conference.

NYPD Commissioner Jessica Tisch said their law enforcement partners in Las Vegas, where Tamura lived, confirmed that the gunman had a “documented mental health history.”

The exact details of his mental health are unclear.

Tamura barged into the building owned by Rubin Management and opened fire in the lobby before making his way to the 33rd floor, where he shot and killed one woman before eventually turning the gun on himself.

He killed four people total, including an NYPD officer in the lobby.