New York City Mayor Eric Adams said on Monday there was an "active shooter" investigation underway in central Manhattan, while the FBI added it was also providing support at what it called an active crime scene.

A man stalked through a Manhattan office tower firing a rifle Monday, killing four people, including a New York City police officer, and wounding a fifth before taking his own life, officials said. The shooting took place at a skyscraper that is home to the headquarters of both the NFL and Blackstone,

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.