A three-page note criticizing the National Football League and referencing a brain disease associated with football was found on the man who opened fire in a midtown Manhattan office building on Monday, New York City police said. The gunman, who police have identified as 27-year-old Shane Tamura, killed four people before shooting himself in the chest on the 33rd floor of the building.
Excerpts from the note, which was found in Tamura’s wallet, were released by the police and condemned the NFL, which has an office in the building where the shooting took place, and accused the league of hiding the dangers of playing football. Investigators believe Tamura was trying to get to the NFL offices but took the wrong elevator, New York Mayor Eric Adams said, according to the Associated Press.
New York Police Commissioner Jessica Tisch told reporters Tamura was a former high school football player who had a “documented mental health history.”
The note also mentioned chronic traumatic encephalopathy (CTE), a brain disease that has been linked to contact sports such as football.
“Study my brain please,” the note said. “I’m sorry.”
What is CTE?
CTE is a brain disease that’s caused by repeated traumatic head injuries, like concussions, according to the Mayo Clinic. The repeated injuries cause permanent damage to nerve cells in the brain, resulting in symptoms such as memory loss, aggression, depression, impaired judgment and impulsive behavior.
The disease gets worse over time, and some experts believe some of the symptoms can take years or even decades to develop after someone has suffered repeated head trauma. There are no official tests for CTE — it can only be officially diagnosed with a brain autopsy after death — nor is there any kind of treatment for those who think they have it. Many of the symptoms associated with CTE are also linked to other neurological conditions, such as post-concussion syndrome (PCS) and Alzheimer’s.
There is a strong connection between CTE and contact sports, such as ice hockey and football; combat sports, such as boxing or martial arts; and military service, according to the Cleveland Clinic. In football specifically, it is very common for players to experience repeated concussions, both during practice and in games.
Boston University’s CTE Center reported in 2023 that out of 376 former NFL players studied by the center, 345, or 91.7%, had been diagnosed with CTE. The announcement of the findings clarified that the data “should not be interpreted to suggest that 91.7 percent of all current and former NFL players have CTE, as brain bank samples are subject to selection biases.”
But it’s not only NFL players who may be at risk of developing CTE. A 2017 study of brains donated by over 200 former football players across all levels found evidence of CTE in those who had played only in high school or college, in addition to those who went on to semiprofessional or professional leagues.
A player’s chances of getting CTE does not depend on what position they play, according to Dr. Ann McKee, a neurology professor at Boston University who studies CTE.
“We’ve now found CTE in former NFL players who played every position except kicker,” McKee told the Associated Press. “While we know on average that certain positions experience more repetitive head impacts and are more likely at greater risk for CTE, no position is immune.”
What the NFL has said about CTE
The first former NFL player to be posthumously diagnosed with CTE was Pittsburgh Steelers offensive lineman Mike Webster in 2002. However, for many years, the NFL denied any link between football and CTE. As more research and studies were published, the NFL’s Mild Traumatic Brain Injury Committee (MBTI) continued to publish its own findings, claiming that CTE diagnoses were more common in boxers and jockeys than football players.
It was not until 2016 that the NFL first acknowledged the link between football-related head trauma and CTE, according to ESPN. The NFL has since tried to implement the use of new protective gear, but it has not been adopted across the league, and its effectiveness is not clear, according to Harvard Public Health.
The impact of CTE on former NFL players
A 2024 Harvard Medical School study found that out of 2,000 former NFL players, about a third of them believed they had CTE but knew they could not be formally diagnosed.
Since 2019, a number of NFL players have either asked to donate their brains to CTE research, or their families have volunteered to do so after their deaths. Some of these players include Dave Duerson, Ray Easterling, Junior Seau, Andre Waters, Aaron Hernandez and Philip Adams, all of whom committed suicide. Like Tamura, Duerson and Seau died of self-inflicted gunshot wounds to the abdomen and chest, respectively. Duerson left a note asking that his brain be “given to the NFL’s brain bank.”
