The individual behind the tragic shooting that claimed four lives in a Midtown Manhattan office building this past July has been posthumously diagnosed with chronic traumatic encephalopathy (C.T.E.). This degenerative brain disease, commonly linked to repetitive head trauma from sports like football, was confirmed by the New York City medical examiner’s office.
C.T.E., which can only be diagnosed after death, was found in the brain tissue of Shane Tamura, the gunman who took his own life after the violent incident at 345 Park Avenue. The medical examiner’s statement indicated “unambiguous diagnostic evidence of Chronic Traumatic Encephalopathy… in the brain tissue,” classifying it as low-stage C.T.E. based on current criteria.
Tamura, a former high school football player, shot himself in the chest after the spree. A note he left behind expressed his motivation as profound anger towards the National Football League, accusing it of concealing the true impact of C.T.E.
According to police, 27-year-old Tamura traveled from his Las Vegas apartment, specifically targeting the building at 345 Park Avenue, which houses the N.F.L. headquarters. His note, partially released by authorities, strongly condemned the National Football League for prioritizing profits over player safety, alleging they hid the dangers of the sport.
Tamura’s family chose not to comment on the medical examiner’s findings. This diagnosis reignites critical discussions surrounding the potential long-term risks associated with playing tackle football, even at the youth level.
Despite not playing football beyond high school, Tamura’s note explicitly referenced C.T.E. and claimed the N.F.L. had deliberately obscured the risks of brain trauma in the sport for financial gain. Police believe he was seeking revenge against the league, whose offices are located in the targeted building.
Over the past two decades, as numerous former football, boxing, and hockey players have been diagnosed with C.T.E., public awareness of these sports’ dangers has grown, and researchers have gained more insight into the disease and its symptoms. However, leaders of the N.F.L. and other sports organizations have historically been reluctant to fully acknowledge the direct link between their sports and brain trauma.
C.T.E. commonly impacts the superior frontal cortex, a brain region crucial for cognitive functions like working memory, planning, and abstract reasoning. It also frequently affects the amygdala, which plays a vital role in emotional regulation, aggression, and anxiety. Typical symptoms include difficulties with impulse and aggression control, varying degrees of dementia, mood swings, impaired judgment, and disorganization.
While most C.T.E. cases have been identified in athletes who engaged in contact and collision sports for 15 to 20 years, enduring countless head impacts throughout their careers, researchers caution that C.T.E. studies are prone to selection bias. This is because most brain donations come from families whose loved ones exhibited symptoms of neurological impairment.
As understanding of the disease evolves, younger athletes’ brains have also been donated, with some showing evidence of C.T.E., though generally less severe than in older players. At 27, Mr. Tamura joins this increasing group of younger individuals diagnosed with the condition.
Regardless of age, researchers remain cautious about directly attributing specific actions, especially murder or suicide, to C.T.E., as numerous other factors can influence such decisions.
Dr. Ann McKee, director of the Boston University C.T.E. Center and a leading expert in brain trauma, has stated that the connection between violent impulsive behavior and C.T.E. is still not well understood, emphasizing the need for further research.
“There is damage to the frontal lobes, which can damage decision making and judgment,” she previously explained. “It can also cause impulsivity and rage behaviors, so it’s possible that there’s some connection between brain injury and these behaviors.”
Several high-profile cases involving former football players committing violent crimes have drawn significant national attention. Notably, Aaron Hernandez, the former New England Patriots tight end, was convicted of murder before taking his own life in jail. Hernandez, who died at 27, was found to have a severe form of C.T.E., with damage comparable to players in their 60s.
Phillip Adams, who tragically shot and killed six people before taking his own life in Rock Hill, S.C., in 2021, also had an “unusually severe” form of C.T.E. He was 32 and had played six seasons in the N.F.L.
Other former N.F.L. players who died by suicide, such as Dave Duerson, deliberately shot themselves in the chest to preserve their brains for study, often leaving notes requesting such examination.
However, researchers stress that these individual cases do not necessarily represent the wider population of people living with C.T.E.
“I would never draw a direct line between someone’s brain pathology and any specific violent act, because the majority of people who have C.T.E. never committed anything like this,” Dr. Daniel H. Daneshvar, chief of brain injury rehabilitation at Harvard Medical School, recently told reporters.
For many years, the risk of developing C.T.E. was thought to be confined to those who endured prolonged careers in professional football, rugby, or boxing, suffering innumerable head blows. More recently, however, it has been diagnosed in younger athletes across various contact sports, some of whom never played professionally or even in college.
A 2023 Boston University study investigated the brains of 152 contact-sport athletes who passed away before age 30, whose families had concerns about brain disease. Over 40 percent of these athletes showed evidence of C.T.E., with most having played no higher than high school or college levels. Of the 63 diagnosed with C.T.E., 48 had played football.
These younger athletes, like their older counterparts, showed tau protein in specific brain regions, a hallmark of C.T.E. However, the tau concentration was lower in younger athletes, and their cognitive symptoms mirrored those of other young athletes not diagnosed with C.T.E. This suggests that smaller amounts of tau may not be the sole cause of their symptoms, and other factors could be at play, according to researchers.
“The message here is that there’s less scientific understanding of what’s driving the symptoms in these younger players, and whether it’s related to brain trauma or perhaps other things,” stated Gil Rabinovici, a professor of neurology and radiology at the University of California, San Francisco, who is working on imaging techniques to diagnose dementia and C.T.E. in living patients. “It’s going to be important to look at other brain changes that are not tau related. We should be very cautious in trying to attribute their behavior to what we find in the brain.”
In the absence of a reliable live C.T.E. test, athletes like Tamura may self-diagnose their cognitive issues as symptoms of the disease. Dr. Rabinovici referenced a survey of 4,180 former professional football players, where 34.4 percent believed they had C.T.E. based on symptoms like headaches, cognitive difficulties, depression, and suicidal thoughts.
Tamura was prescribed medication for anxiety, depression, and bipolar disorder, as confirmed by his mother and New York police officials. His suicide notes revealed an obsession with brain injuries, and he believed his deteriorating mental health stemmed from playing football and sustaining repeated head impacts.
Dr. Rabinovici and other researchers have dedicated years to developing a test for C.T.E. in living individuals. Promising avenues include blood tests and brain imaging capable of detecting the tau protein in specific brain areas, with progress described as “slow and steady.”
Following years of public relations challenges and mounting evidence linking football to C.T.E., the N.F.L.’s chief health and safety official publicly acknowledged the connection in 2016. Since then, the league has actively encouraged children away from traditional tackle football, promoting safer tackling techniques and advocating for flag football as an alternative.