NYC Mass Shooter, Ex-SoCal Football Standout, Linked NFL And CTE In Suicide Note: Reports

LOS ANGELES, CA — The gunman who killed four people in a Manhattan skyscraper that houses NFL headquarters before shooting himself Monday was a former Southern California high school football player who claimed in a suicide note to suffer from CTE and expressed grievances involving the league, according to reports.

Shane Tamura, 27, entered the Park Avenue tower at around 6:30 p.m. and began "spraying" the lobby with gunfire, according to police. He headed to the 33rd floor and continued firing, killing four people before shooting himself, New York City officials told reporters.

Tamura, who was most recently living in Nevada, attended two Los Angeles County High Schools: Golden Valley High School in Santa Clarita and Granada Hills Charter High School, where he was a standout running back, KTLA reported.

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Tamura's body was found with a note in his pocket requesting that his brain be studied for the effects of CTE — the brain disease that's been linked to repeated head trauma in former football players, CNN reported.

The note also mentioned the league. Authorities “have reason to believe that he was focused on the NFL,” New York Mayor Eric Adams said, according to the New York Times.

Police said Tamura had a "documented mental health history," but authorities were still investigating the motive for the attack.

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Walter Roby, one of Tamura's former coaches at Granada Hills, said he was "just blown away right now" at the news of the shooting, NBC News reported. He described Tamura as a skilled running back and "a great player" who was "real elusive, real agile. He came in, worked hard, kept his nose down. He was a quiet kid, well-mannered, very coachable. Whatever needed to be done, he would do."

He rushed for 616 yards and five touchdowns on 126 carries and caught 25 passes for 229 yards and two touchdowns as senior for Granada Hills Charter High School in 2015, according to the high school sports website MaxPreps.

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Tamura rushed for 774 yards and 11 touchdowns on 139 carries for Golden Valley of Santa Clarita as a junior in 2014, according to MaxPreps.

Former classmate Caleb Clarke told NBC News that Tamura "never came off violent. You never would have thought violence was something you'd associate with him. Everything he said was a joke."

Tamura had two Mental Health Crisis Holds in Nevada, in 2022 and 2024. Those holds typically allow for someone to be detained for up to 72 hours if they are thought to be a danger to themselves or others, ABC 7 in New York reported.

City News Service contributed to this report.