New York City is mourning NYPD Officer Didarul Islam and three other people killed in Monday's shooting inside an office building at 345 Park Ave.

A shooting Monday at an office building in New York City that is home to the Blackstone investment firm and the NFL left four people dead, including an NYPD officer.

NFL commissioner Roger Goodell called Monday’s shooting in New York City an “attack on humanity” ahead of Thursday night’s annual Hall of Fame game in Canton, Ohio.

Roger Goodell was emotional on Thursday as he publicly addressed the deadly shooting that took place inside 345 Park Avenue, the building that houses the NFL’s New York offices, earlier this week. The NFL commissioner did not attend Thursday’s Hall of Fame game in Canton,

The NYPD continues to work with investigators across the country to learn more about the gunman in Monday's deadly Midtown office shooting.

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