A man holding a rifle walks into an office building at 345 Park Avenue shortly before a shooting that killed several people, in the Midtown Manhattan district of New York City, U.S. in a still image taken from surveillance video. Surveillance Camera/Handout via Reuters]

The man who killed four people with a semi-automatic rifle while rampaging through a Midtown Manhattan office tower carried a note with him that appeared to blame the National Football League for his degenerative brain disease, New York Mayor Eric Adams said on Tuesday.

Police have identified the shooter as Shane Tamura, a 27-year-old Las Vegas resident with a history of mental illness.

Tamura killed two security officers and two office workers from firms in the building before ending the Monday evening massacre by shooting himself in the chest on the 33rd floor of the Park Avenue office tower.

It was the deadliest mass shooting in New York City in a quarter of a century.

The NFL has its headquarters in the skyscraper alongside major financial firms, but Tamura apparently entered the wrong elevator bank and ended up in the offices of Rudin Management, a real estate company that owns the building, where he killed one Rudin employee, the mayor said.
“The note alluded to that he felt he had CTE, a known brain injury for those who participate in contact sports,” Adams told CBS News. “He appeared to have blamed the NFL for his injury.”

Chronic traumatic encephalopathy is a serious brain disease with no known treatment that can be caused by repeated bangs to the head while playing contact sports. It has been linked to aggression and dementia.

The NFL has paid more than $1 billion to settle concussion-related lawsuits, opens new tab with thousands of retired players after the deaths of several high-profile players in the top professional American football league.

Tamura was never an NFL player, but online records show he played football at his California high school and was a varsity player at a Los Angeles charter school until graduating in 2016, according to school sports databases.

The note found in his wallet said his football career was cut short by his brain injury and that the NFL had not done enough to address CTE in the sport, Bloomberg News reported.

A former coach, Walter Roby, told Fox News that Tamura was a “quiet, hard worker” and one of his “top offensive players” during the year he spent on the team at Granada Hills Charter School.

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