A New York City police officer and three other people were killed in a shooting in Midtown Manhattan on Monday evening, police confirmed at a late-night news conference.

Didarul Islam, a 36-year-old NYPD officer, was off duty and working a security job when he was fatally shot by a gunman who opened fire at the 345 Park Avenue office building on Monday.

Police lined up four rows deep in front of a mosque on Thursday to pay respects to a fellow officer who was among the victims of a gunman's rampage at a New York City office tower. Fire trucks bore a huge American flag down the street ahead of services for Officer Didarul Islam,