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.

On Monday evening, 27-year-old Shane Devon Tamura calmly walked into a Midtown Manhattan skyscraper armed with an M4-style rifle and opened fire, killing four people, including a cop, Didarul Islam, before shooting himself in the chest.