The New York City office building that was the site of a mass shooting Monday had significant security measures in place.

Officials said the gunman fatally shot himself after his attack, which set off a chaotic scene that rippled out into the heart of Manhattan during rush hour.

Police have identified the man who they say entered a Midtown Manhattan office building wearing body armor and opened fire, killing four people with a high-powered rifle, as Shane Devon Tamura.

This is a breaking news story. For latest updates, please go to our live blog. An NYPD officer and at least four other victims were killed in a shooting at an office skyscraper in midtown Manhattan Monday evening,