A gunman who killed four people when he stormed a skyscraper in the heart of New York on Monday evening left a note that appeared to blame the National Football League (NFL) for a brain injury, the city's Mayor Eric Adams has said.

A gunman who killed four people inside a Manhattan office tower blamed his mental health problems on the National Football League and intended to target the league’s headquarters upstairs but took the wrong elevator,

A man exited a double parked BMW with an M4 rifle and then walked toward the skyscraper that is home to the headquarters of both the NFL and Blackstone, one of the world’s largest investment firms, as well as other tenants on Monday evening, according to surveillance video.