Investigators are combing through evidence in the wake of New York City’s deadliest mass shooting since 2000, trying to figure out more about the gunman who unleashed an assault-style rifle in Midtown,

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.

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,