NEW YORK: A man with a rifle killed an off-duty New York City police officer and three other people before taking his own life at a Manhattan office tower on Monday, according to officials.

Law enforcement officials were working to unravel what took place and why this location may have been targeted in a city that had recently announced it was on pace to have its fewest people hurt by gunfire than any year in recent decades.

What happened?

A man exited a double parked BMW with an M4 rifle and then walked toward the building on Monday evening, according to surveillance video.

He quickly opened fire on the NYPD officer as he entered the building before shooting a woman who tried to take cover, police Commissioner Jessica Tisch said at a news conference on Monday night. He then started “spraying” the lobby with gunfire.