Follow along for live updates on the New York City shooting, where police investigate motive after five people, including the gunman, were killed in the Monday shooting.

Investigators plan to question a man who supplied parts for a gun used in the shooting at a Manhattan office building that houses the National Football League’s headquarters, New York City Police Commissioner Jessica Tisch said Tuesday.

Four victims, including an NYPD officer and a Blackstone executive, were killed in an NYC shooting at 345 Park Avenue.

The first word of a deadly shooting spree during rush hour in Midtown Manhattan on Monday came into the New York 911 system at 6:28 p.m. (2228 GMT) and more calls soon flooded in, according to a detailed recount of the shooting that left at least five dead,

FBI Deputy Director Dan Bongino said agents from the bureau’s New York field office were responding to the area to provide support.