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.

As for security, badges and sign-in lists for visitors became standard fare in New York office buildings after the Sept. 11 attacks nearly a quarter-century ago. Many buildings installed turnstiles between guard desks and building elevators. In recent months, some buildings had stepped up their precautions even more because of the war in Gaza.

A man exited a double parked BMW with an M4 rifle and then walked toward the skyscraper that is home to the headquarters of both the NFL and Blackstone, one of the world’s largest investment firms, as well as other tenants on Monday evening, according to surveillance video.