No motive has been announced. A suicide note was found expressing grievances with the NFL and saying Tamura suffered from CTE, a source said. Follow for live updates.

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.

Four people were killed and a fifth was injured in a mass shooting at a Midtown Manhattan office building on Monday.

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,

Two teams NYPD detectives headed to Las Vegas Tuesday, to execute search warrants at Shane Tamura's home and at a gun store where he legally purchased a revolver on June 12 using a Nevada concealed carry permit,

NYPD officials are heading to Las Vegas to investigate the gunman who killed four people in a Midtown Manhattan skyscraper.

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,

A New York police officer, a “beloved” security guard and a senior executive with investment firm Blackstone were among four people killed Monday when a lone gunman stormed a sprawling office tower in Midtown Manhattan and opened fire.

The mayor of New York says Shane Devon Tamura may have been targeting the headquarters of the NFL when he opened fire at a skyscraper in midtown Manhattan. A three page suicide note found in Tamura’s wallet and reviewed by NBC News contains several references to the degenerative brain disease CTE,

Bankers and traders returned to work on a somber Tuesday morning in Midtown Manhattan, New York's financial epicenter, one day after a shooting that killed four people, including a senior Blackstone executive.