Officer Didarul Islam, 36, who was guarding the building on a paid security job when he was killed, had served as a police officer in New York City for over three years. He was an immigrant from Bangladesh and was working a department-approved building security job when he was shot.

An attorney for the man who sold a rifle used in the Monday mass shooting in New York City said Thursday that the sale of the firearm to the gunman was done in compliance with state and federal law.

Authorities say the man who killed four people at a Manhattan office building bought the rifle he used in the attack and the car he drove across country from his supervisor at a Las Vegas casino