The gunman who suspected he had CTE when he killed four people and himself in a Manhattan office building in July did in fact have the degenerative brain disease, a medical examiner said Friday.
Shane Devon Tamura, 27, who played high school football, had "unambiguous diagnostic evidence" of low-stage CTE, or chronic traumatic encephalopathy, the New York City medical examiner said.
The brain disease is caused by repeated head injuries and is most commonly associated in the U.S. with NFL players. But researchers say Tamura is far from the first young athlete to develop CTE despite not having played sports after high school or college.
“We know that we have a lot of cases like this. We know high school football players can get CTE,” said Chris Nowinski, co-founder and CEO of the nonprofit Concussion Legacy Foundation.
Nowinski said Tamura's findings should be a wake-up call to football coaches and other leaders in the sports world and trigger stricter guidelines for America’s most popular sport.
"We don't need any more research to convince high school coaches to change the rules of the game," he said. "There needs to be a will to do it."
The medical examiner conducted a brain examination as part of Tamura’s autopsy after authorities say the attacker left a note at the scene of the July 28 shooting, expressing anger that his mental troubles may have been linked to playing football and requesting his brain be studied for CTE.
Authorities said Tamura was trying to target the headquarters of the NFL, which is in the Park Avenue building where the shooting took place.
Tamura played high school football in California about a decade ago and frequently took hits from other players in his positions as running back and defensive back, his former teammates and an ex-coach previously told NBC News.
Nowinski said news coverage of CTE cases has largely centered around high-profile NFL players, which he said creates the false perception that the issue only affects professional athletes. But he said experts who study brain injuries know that high school athletes are also at risk.
A 2023 study, led by Dr. Ann McKee, a top neurologist in CTE research, confirmed that CTE can be found in young contact sport athletes. Of the 152 brains of athletes under the age of 30 that researchers examined, CTE was found in about 41% of them, the study found. The ages of the 152 brain donors ranged from 13 to 29.
The brains belonged to young, deceased, contact sport athletes who had symptoms while alive. Their brains were donated to the Understanding Neurologic Injury and Traumatic Encephalopathy (UNITE) Brain Bank.
It's a pressing concern, said Nowinski, who played college football for Harvard University and sustained a career-ending concussion in 2003 as a WWE professional wrestler.
Nowinski said he hopes Tamura’s case leads high school football associations to educate coaches and players about CTE and set stricter limits on how many times, and how hard, athletes can be hit in the head.
"We’d be insane not to enact efforts to prevent CTE," he said.
An estimated over 300,000 high school athletes in the country suffer a concussion each year, the National Federation of State High School Association has previously said. In 2019, it recommended limiting full contact during practice sessions and limiting the total number of quarters or periods played per week in sports like football and ice hockey.
The association said it has initiated numerous measures in the last 10 to 15 years to reduce the risk of injury in high school football players, including prohibiting helmet-to-helmet hits. It declined to comment on Tamura’s CTE diagnosis.
The NFL first acknowledged the link between CTE and football in 2016. In a statement Friday, the NFL said it continued to "grieve the senseless loss of lives, and our hearts remain with the victims’ families and our dedicated employees."
