There were 23 shell casings and 13 bullet fragments recovered from the lobby of 345 Park Avenue and 24 spent shell casings on the 33rd floor, police said.

NEW YORK -- A 27-year-old man wearing body armor and carrying an M4 assault rifle shot and killed four people, including off-duty New York Police Department Officer Didarul Islam, who was working security in a Midtown Manhattan office building, officials said during a press conference Monday evening.