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.

New York City Mayor Eric Adams said on Monday there was an "active shooter" investigation underway in central Manhattan, while the FBI added it was also providing support at what it called an active crime scene.

Mayor Eric Adams on X: "Tonight, our city is reeling and four innocent families are mourning, including the family of NYPD Officer Didarul Islam, who was killed at 345 Park Avenue. He represented the best of New York City, an immigrant from Bangladesh who put on a uniform to protect and serve us all."