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 City is mourning NYPD Officer Didarul Islam and three other people killed in Monday's shooting inside an office building at 345 Park Ave.

Flags across New York are flying at half-staff to honor the victims of Monday’s deadly Midtown Manhattan office shooting, including an NYPD officer.