Mourners packed a Bronx mosque to pay respects to a New York City police officer who was among the four people killed when a gunman opened fire this week at the Manhattan skyscraper that houses the NFL's offices.

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.

A New York City police officer and an executive at an investment firm are among the four people killed by a gunman at a Manhattan office tower.

Investigators plan to question a man who supplied parts for a gun used in the shooting at a Manhattan office building that houses the National Football League’s headquarters.