Shane Tamura killed four people at a Manhattan office building Monday, including Blackstone executive Wesley Lepatner and New York City police officer Didarul Islam. The head of the NYPD said investigators plan to question a man who supplied parts for the gun that was used in the attack.

The survivor, who cleaned the office building, said she pleaded for her life as the gunman pointed his gun at her and managed to hide in a supply closet.