NFL headquarters shooting New York Screengrab via NBC

The gunman who killed four people in Manhattan before taking his own life on Monday was targeting the NFL headquarters, New York City mayor Eric Adams told reporters on Tuesday.

According to the Associated Press, police said that the gunman, who has since been identified as Shane Tamura, had a history of mental illness. A rambling note that was found on his body suggested he had a vendetta against the NFL over an unverified claim that he suffered from chronic traumatic encephalopathy (CTE) after playing high school football in California more than two decades ago. The AP reports that the note stated that his brain should be studied and specifically referenced the NFL.

The incident occurred just before 6:30 p.m. on Monday at a Manhattan skyscraper located at 345 Park Avenue, which houses both the NFL headquarters and the Blackstone investment firm. Surveillance video showed the gunman entering the building carrying an M4 rifle, which he used to kill a police officer who was working a corporate security detail before spraying the lobby with gunfire, striking a woman, according to Police Commissioner Jessica Tisch.

Tisch said that the gunman then made his way to the elevator bank, shooting a security guard and another man in the process. He then took the elevator to the 33rd floor offices of the company that owned the building, Rudin Management, where he shot and killed one person before shooting himself.

In a letter sent to employees overnight, NFL commissioner Roger Goodell addressed the shooting, revealing that one of the people shot worked for the league. Per Goodell, the employee was “seriously injured” in the shooting and is currently in stable condition at the hospital.

“NFL staff are at the hospital and we are supporting his family,” Goodell wrote in the memo, which was obtained by multiple media outlets, including ESPN. “We believe that all of our employees are otherwise safe and accounted for, and the building has nearly been cleared.”

The NFL commissioner added that the league headquarters would have an increased security presence in the days and weeks ahead. He also said that league employees in New York should work remotely on Tuesday and that it was understandable if any took the day off.

“Every one of you is a valued member of the NFL family,” Goodell wrote. “We will get through this together.”

About Ben Axelrod

Ben Axelrod is a veteran of the sports media landscape, having most recently worked for NBC's Cleveland affiliate, WKYC. Prior to his time in Cleveland, he covered Ohio State football and the Big Ten for outlets including Cox Media Group, Bleacher Report, Scout and Rivals.