Topline
Shane Tamura, the gunman who opened fire at NFL headquarters in Manhattan in July and killed four people, was diagnosed posthumously with chronic traumatic encephalopathy (CTE), a brain disease linked to repeated head trauma.
Recent brain scans of NFL hall of famer Joe DeLamielleure, who was diagnosed with CTE, the brain injury that is affecting so many former football players. (Jeff Siner/Charlotte Observer/MCT)
Tribune News Service via Getty Images
Key Facts
The New York City medical examiner confirmed Tamura’s brain tissue shows evidence of low-stage CTE, a brain disease that damages parts of the brain that control judgement, impulse regulation, and aggression — and has been linked in recent years to physical injuries including those sustained by football players.
Tamura died by suicide after fatally shooting an NYPD officer, a security guard, a Blackstone executive, and a Rudin Management employee; an NFL staffer was injured.
A former high school football player, Tamura left a note accusing the NFL of hiding the dangers of brain trauma and asked that his brain be studied, suspecting he had CTE, according to the NYT.
Scientists link CTE to changes in the frontal lobe and amygdala, areas tied to judgement and impulse control.
In 2016, NFL executive Jeff Miller publicly acknowledged for the first time that football-related head trauma is linked to CTE, making the admission during a congressional committee roundtable and later reaffirming it in an official statement.
Since then the NFL has been subject to scrutiny and in response the league has worked to enhance player safety by upgrading helmet designs and adopting stricter testing standards.
What Is Cte?
Chronic traumatic encephalopathy is a degenerative brain disease linked to repeated head trauma, most often seen in contact sports and military service. It is driven by brain changes such as atrophy and tau protein buildup, a protein in neurons that normally stabilizes brain cells but in CTE misfolds and clumps into tangles. These tangles disrupt cell function and eventually cause cell death. Diagnosis is only possible after death, though doctors use the term “traumatic encephalopathy syndrome” for symptoms seen in those affected – mood and behavioral problems in younger patients, cognitive decline in older ones. There is no cure, however, researchers are developing brain scans and blood tests to catch it earlier.
Tangent
Several former NFL players were diagnosed with CTE. Aaron Hernandez, the Patriots tight end convicted of murder, killed himself in prison at 27 and was found with brain damage typical of men in their 60’s. Phillip Adams, who played six NFL seasons, fatally shot 6 people in South Carolina in 2021 before taking his own life. Also, Dave Duerson, a Super Bowl champion, also died by suicide, shooting himself in the chest and also left a note asking that his brain be studied.
Crucial Quote
“When the NFL realized the data showing the risk of CTE in football wasn’t hurting their bottom line or their fan base, the pretense stopped,” wrote Dr. Ann McKee, director of the Boston University CTE Center in response to an X post citing a high profile concussion case as the moment the league stopped denying the link between football and brain trauma.
87%
A landmark study examining the brains of 177 former professional football players found evidence of CTE in nearly 9 out of 10 cases.
Source: https://www.forbes.com/sites/martinacastellanos/2025/09/26/what-to-know-about-ctethe-brain-disease-diagnosed-in-midtown-gunman/
