New York City is mourning an NYPD officer and three other people killed in Monday night's shooting inside an office building in Midtown Manhattan. Officer Didarul Islam was in uniform working as a security guard for a private company at the time of the shooting,

Didarul Islam, 36, was a father of two, with a third on the way, and was working a second job as a security guard at the building where shots rang out.

New York's mayor says the father of two was doing what he did best and protecting New Yorkers when he was shot dead on Monday evening.