New York City is mourning an NYPD officer and three other people killed in Monday'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,

The police officer who was killed when a gunman opened fire in a Manhattan building was a dedicated father who was working a second job as a security guard.

Five people were shot when a gunman opened fire at a Manhattan skyscraper on July 28. Here's what we know so far about the victims.