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 are examining why the gunman who killed four people before taking his own life at a New York City office tower targeted the National Football League and whether he suffered from a brain disease.

Blackstone told employees on Friday it will reopen its New York headquarters on August 4, a week after shuttering it in the wake of a shooting that killed four people including one of its executives.