Shane Devon Tamura, 27, was identified as the shooter who had driven across the country from Nevada and arrived in New York City hours before the shooting, according to officials. Tamura shot himself in the chest on the 33rd floor of the building before police found him.

New York City Police Chief John Chell joins "CUOMO" to talk about the events of what happened on the ground after Shane Tamura fatally shot himself and three others in Manhattan on Monday. #nycshootin

"Someone with an AR-15 intent on killing anything he saw last night, that's hard to deal with," said the NYPD's John Chell.