Shane Devon Tamura Highlights NFL's Head Trauma Problem

Newsweek

29-07-2025

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The NFL's problem with head injuries is in the spotlight after a gunman killed four people before turning the firearm on himself at the league's headquarters in New York on Monday.
The shooter, 27-year-old Shane Devon Tamura from Las Vegas, was found with a suicide note, alleging that he suffered from chronic traumatic encephalopathy (CTE), a progressive brain disorder related to head injuries, which has been associated with football. It is not yet clear if Tamura actually had CTE.
"Terry Long football gave me CTE and it caused me to drink a gallon of antifreeze. You can't go against the NFL, they'll squash you," the note allegedly read, according to sources that spoke to CNN. The note reportedly continued that Tamura wanted his brain studied.
Terry Long was a former football player for the Pittsburgh Steelers, who died by suicide in 2005 after drinking antifreeze. An autopsy revealed he had CTE.
Multiple sources also allegedly told CNN that Tamura had played competitive football when he was younger.
A file photo shows an NFL player.
A file photo shows an NFL player.
Lindsey Wasson/AP
What Is CTE?
"CTE is a progressive neurodegenerative disease that develops as a result of repeated impacts over time, leading to the buildup of abnormal tau protein and progressive brain degeneration," Damian Bailey, a professor of physiology and biochemistry and director of the Neurovascular Research Laboratory at the University of South Wales, told Newsweek.
Cumulative exposure to repeated sub-concussive or concussive impacts "significantly increases the risk" of developing the disease, he said.
Other factors may influence susceptibility, he said, such as genetic factors and substance abuse, but "repetitive head trauma is currently the only confirmed environmental cause," meaning military personnel and athletes engaged with contact sports are most at risk.
Bailey said it's important to note that contact doesn't have to be directly to the head in order to pose a problem, and could be a shoulder impact, for example.
Also, 90 percent of concussions don't involve a loss of consciousness, he added, "so the damage is cumulative and often goes undetected."
CTE can have wide-ranging effects on a person's life, potentially leading to severe mood instability including paranoia, suicidal or homicidal ideation, emotional dysregulation, aggression, impulsivity, and impaired judgement, Bailey said.
The disease, "in rare but tragic cases, may contribute to violent behavior when combined with other stressors and access to weapons," he added.
As diagnosis of the condition requires thorough examination of brain tissue, it can only be done after death, but experts have developed a clinical criteria for a group of symptoms associated with CTE, known as traumatic encephalopathy syndrome, to help inform patient care.
It is crucial to note that, in light of the shooting on Monday evening, even if Tamura had CTE, "that would not justify these heinous actions," Dr. Daniel H. Daneshvar, co-director of the Mass General Brigham Sport Concussion Clinic, and professor at Harvard Medical School, told Newsweek.
"While understanding brain health is vital, linking a single act of violence directly to CTE without evidence risks misunderstanding both the disease and the tragedy," he added.
He said that there is "no direct, one-to-one connection between CTE pathology and a specific action," meaning that "many people with CTE never engage in violence, and most violent acts are not caused by CTE."
Findings of CTE Among NFL Players
Football is a contact sport that "involves frequent, repetitive head impacts, including many that do not cause acute symptoms, leading to cumulative brain trauma over time," Bailey said.
"The combination of high-speed collisions in very powerful players, repeated sub-concussive hits, and a culture that historically downplays concussions increases the risk of long-term brain injury and corresponding CTE," he added.
CTE typically develops following "thousands of head impacts over years," Daneshvar said.
"As a result, the number of years and intensity of exposure matter—research has shown a dose-response relationship, where the risk and severity of CTE increase with more years of experiencing repeated head impacts," he said.
This means that someone who only played through high school typically has a much lower level of exposure than a professional athlete, he added.
In a 2024 study of almost 2,000 former players, researchers found that 34 percent believed they had CTE—although, given it cannot yet be diagnosed in a living person, they did not know for certain.
Those that believed they had the condition were found to have higher rates of cognitive problems, mental health disorders, chronic pain, head injury and low testosterone.
Around 25 percent of those who believed they had CTE also reported suicidality, while 5 percent of those who did not believe they had CTE reported the same.
In a 2023 study, Boston University CTE Center found that 345 out of 376 former NFL players who donated their brains to the center for investigation had CTE—equating to 90 percent of them having the disease.
However, the researchers noted that this does not suggest 90 percent of NFL players have the condition, as it can only be diagnosed after death, and prevalence remains unknown.
Comparatively, a 2018 Boston University study conducted on 164 men and women from the general population found only one person had CTE—and the lone case was a former college football player.
The findings suggest that, while cases of CTE seem to be extremely low in the general population, cases appear to be significant among former NFL players—tying the disease to the sport in a strong association.
Other sports have also been associated with the condition, with documented cases of CTE in hockey, boxing, rugby union, wrestling, soccer, horse racing and mixed martial arts, Bailey said.
What Has NFL Said About CTE?
An NFL official first acknowledged the link between CTE and football in 2016, during a roundtable organized by the U.S. House of Representatives' Committee on Energy & Commerce.
In the meeting, Jeff Miller, the league's senior vice president for health and safety, was asked if there was a link between the two, and, according to ESPN, Miller confirmed that there was.
While previous officials had referred to the risk of concussions leading to long-term problems, it marked the first time the NFL addressed that frequent head trauma could lead to CTE.
An NFL memo released that same year also reported that the league had "recognized for years that studies, including those done at Boston University, have identified retired players who were diagnosed with CTE following their deaths," and that the league has helped to fund the university's research, according to NBC Sports.
However, while the NFL had spent millions on concussion research, it has spent comparatively very little on CTE studies, ABC News reported.
Per the outlet, in 2017, $100 million was invested in concussion research by the NFL, while they had only funded one study on CTE—and that focused on jockeys rather than football players.
The 2016 memo added that research is still in its "infancy" and said that the studies completed have been based on "a largely self-selected population," raising an issue of "selection bias," according to NBC Sports.
Per the outlet, the NFL memo then stated "there is no reliable evidence on the incidence or prevalence of CTE," meaning the league could not provide any "reliable statement" on the risk of CTE in the sport.
Newsweek has contacted the NFL via email for comment.
What Needs To Be Done?
Some focus has been placed on reducing concussions in the sport—with the NFL allowing players to wear Guardian Caps, extra head protection intended to reduce head injuries, during play as well as in practice. Reports have also indicated a drop in concussions in the sport.
Yet, little has been done about tackling the broader risk of CTE in football. This could be down to multiple factors, such as "financial interests, cultural resistance to changing traditional gameplay, lack of immediate visible consequences, limited awareness or denial of the risks, and the complexity of fully understanding and diagnosing the condition which currently takes place at autopsy," Bailey said.
However, he said that sports organizations and governing bodies "should implement stricter safety protocols, improve concussion detection and management, enforce rule changes to reduce head impacts, invest in education for players and coaches, and support ongoing research to better understand and prevent CTE."
"We are currently running to stand still given the prevalence of contact in sport and I anticipate seeing an explosion of clinical cases," he added.
If you or someone you know is considering suicide, contact the 988 Suicide and Crisis Lifeline by dialing 988, text "988" to the Crisis Text Line at 741741 or go to 988lifeline.org