Park Avenue gunman Shane Tamura, who killed an NYPD officer and three others before taking his own life in a midtown Manhattan skyscraper, did — as he contended in his suicide note — suffer from the degenerative brain disease known as CTE, which is often linked to concussive football injuries, the city Medical Examiner said Friday.
A postmortem examination of Tamura’s brain “has found unambiguous diagnostic evidence of Chronic Traumatic Encephalopathy, also known as CTE,” the Office of the Chief Medical Examiner said in a statement.
“The findings correspond with the classification of low-stage CTE, according to current consensus criteria,” the ME added. “CTE may be found in the brains of decedents with a history of repeated exposure to head trauma. The science around this condition continues to evolve, and the physical and mental manifestations of CTE remain under study.”
Footage obtained by the Daily News shows Shane Tamura carrying an assault rifle before entering 345 Park Ave. in Manhattan on Monday, July 28, 2025. (Obtained by Daily News)
Julie Bolcer, spokeswoman for the ME’s office, said, however, that the “ME cannot say how (his condition) factored into the incident.”
“The ME,” she added, “is just answering the question of whether the perpetrator had the condition.”
One in three former National Football League players, according to a recent study, believe they have CTE. The neuropathological condition is linked to repeated head trauma but can only be diagnosed through a postmortem exam.
The NFL said it still grieves the victims of the Tamura’s mass shooting.
“There is no justification for the horrific acts that took place,” the statement said. “As the medical examiner notes, ‘the science around this condition continues to evolve, and the physical and mental manifestations of CTE remain under study’.”
Tamura, 27, shocked the city July 28 when he walked into a Midtown office skyscraper at 345 Park Ave. toting an M-4 assault rifle and opened fire on several people, before taking his own life.
NYPD police officers are pictured outside 345 Park Ave. on Tuesday, July 29, 2025 in New York City, after a shooting inside the office building a day earlier. (Barry Williams / New York Daily News)
The NFL headquarters is located on four floors inside the building and police believe Tamura, who also had a history of mental illness, was targeting the organization, blaming it for his condition, even though he never played professional football. There was no indication he ever played football beyond high school, officials said.
Stepping into the lobby, Tamura killed Police Officer Didarul Islam, building security guard Aland Etienne and Wesley LePatner, a Blackstone senior executive.
He also shot and wounded an NFL employee, Craig Clementi, though police believe he did not know it at the time.
Tamura then got on the elevator, apparently intent on shooting up the NFL offices, but got off on the 33rd floor, the wrong floor, and instead shot dead Rudin Management executive Julia Hyman before killing himself with a shot to his chest.
His suicide note, scribbled on three pages from different daily planner inserts and to-do lists, was folded neatly in his wallet as he carried out the shooting rampage, cops said.
“CTE. Study my brain please,” Tamura wrote in the note. “The league knowingly concealed the dangers to our brains to maximize profits. They failed us.”
His note referenced a PBS documentary that investigated CTE and profiled NFL players who may have suffered from it. He also wrote about Terry Long, a former offensive lineman for the Pittsburgh Steelers, who at first was said to have died in 2006 of cerebral meningitis related to the CTE he was suffering from. A coroner later determined he committed suicide by drinking antifreeze.
“Football gave me CTE and it cause me to drink a gallon of antifreeze,” Tamura wrote.
“You can’t go against the NFL,” he added. “They’ll squash you.”
Granada Hills football player Shane Tamura is interviewed after a game on Sept. 18, 2015. (Southern California News Group file photo)
A source close to Tamura’s family told ESPN in August that Tamura began playing tackle football at age 6 and continued through high school in the Los Angeles area before moving to Nevada, where he worked in private security at a Las Vegas casino.
The source also said Tamura suffered from mental health issues as an adult, including headaches, and took injections in the back of his head to deal with the constant pain he suffered.
While he was living in Las Vegas, cops were twice called to Tamura’s home after he claimed he felt suicidal, police in Nevada said.
On Sept. 12, 2022, Tamura was hospitalized after he contemplated suicide “due to numerous life and family issues,” according to Las Vegas police documents shared with the Daily News. His worried mother called 911 that afternoon reporting her son had a pistol in his backpack.
While being questioned by the 911 operator, Tamura’s mother said he takes sleeping pills for insomnia and was “under a doctor’s care for depression, sports concussions, chronic migraines and insomnia,” according to the 911 call.
He also had a mental health hold in 2024 and was arrested in 2023 at the Red Rock Casino in Henderson, Nevada, following a disagreement about showing identification following casino winnings. Prosecutors declined to charge Tamura in the 2023 case.
A study several years ago diagnosed CTE in the brains of more than 320 former NFL players, including New England Patriots star Aaron Hernandez, who took his own life after he was convicted of a 2013 murder.
The ME’s report comes as the City Council mulls over a new bill introduced Thursday that would require private security guards receive active-shooter training and earn higher wages.
The new bill is named the “Aland Etienne Safety and Security Act,” in honor of the security guard killed in the Park Ave. shooting.
Originally Published: September 26, 2025 at 1:34 PM EDT