Shane Tamura, the Park Ave. gunman who killed an NYPD officer and three others before taking his own life, left behind a suicide note saying he suffered from CTE, a brain injury often linked to playing football, and was targeting the NFL — but took the wrong elevator, officials said Tuesday.

Shane Tamura said he had CTE. His claim, which is unproven, has again put a spotlight on the NFL's troubling history with its players and the disease.

We have reason to believe he was focused on the NFL agency that was located in the building,” New York City Mayor Eric Adams said during an interview on MSNBC Tuesday.

At least two reported shot after gunman entered New York Midtown building where Blackstone and NFL based - Large numbers of police seen outside Manhattan skyscraper

At least one police officer and one civilian were shot inside 345 Park Avenue in New York City, according to NBC News. "New Yorkers: there is an active shooter investigation taking place in Midtown right now," New York Mayor Eric Adams wrote on X. The New York Police Department advised people to avoid the area.