A gunman who opened fire inside a Midtown Manhattan office building on Monday afternoon—killing four people including an NYPD officer—may have been specifically targeting the NFL over its long-standing controversies surrounding CTE and brain trauma in football.

The incident occurred at 345 Park Avenue, the building that houses the NFL’s league headquarters on its fifth floor. According to multiple reports including CNN, ABC News, and NY1, the suspect, Shane Devon Tamura, entered the lobby armed with an M4 rifle and opened fire before taking an elevator to the 33rd floor, where he shot another victim and then died by suicide.

Gunman Allegedly Motivated by NFL-Related CTE Grievances

A law enforcement official briefed on the investigation told CNN that Tamura left behind writings suggesting he had deep grievances with the NFL regarding its handling of chronic traumatic encephalopathy, or CTE. Sources say Tamura was a former competitive football player in his youth and may have believed that long-term head trauma had affected his mental health.

What Is CTE?

What is CTE is a question many are asking following the shooting. Chronic Traumatic Encephalopathy (CTE) is a degenerative brain condition caused by repeated blows to the head. It has been found in athletes—especially football players—even in those who have never been formally diagnosed with a concussion.

According to the Concussion Legacy Foundation, symptoms typically begin years or even decades after the brain has been exposed to trauma. These symptoms can include:

• Memory loss

• Confusion

• Impaired judgment

• Impulse control problems

• Aggression

• Depression

• Suicidal thoughts

• Progressive dementia

Dr. Ann McKee, director of the UNITE Brain Bank at Boston University, has conducted pioneering research into CTE. She notes that the condition closely resembles early-onset Alzheimer’s in its cognitive and behavioral impact.

NFL Players Diagnosed With CTE

CTE has been at the heart of some of the NFL’s most public health controversies. According to Boston University’s CTE Center, as of 2023, 345 out of 376 former NFL players studied—over 91%—were posthumously diagnosed with CTE.

Prominent NFL players diagnosed with or linked to CTE include:

• Junior Seau – Hall of Fame linebacker

• Aaron Hernandez – Former Patriots tight end

• Demaryius Thomas – Pro Bowl wide receiver

• Frank Wycheck – Former Oilers/Titans tight end

• Irv Cross – Defensive back and TV analyst

• Vincent Jackson – Former Chargers and Bucs wideout

• Chris Henry, Terry Long, Jovan Belcher, and Conrad Dobler, among others

NFL’s Controversial History With CTE

The NFL has faced criticism for decades over how it handled brain injuries and downplayed the long-term risks of repeated hits. A landmark class-action lawsuit in 2013 led to a settlement that has paid out over a billion dollars to former players suffering from CTE-related conditions, though critics argue the league has not done enough.

While the motives behind Monday’s shooting are still under investigation, the potential CTE connection underscores the ongoing mental health and safety issues tied to football’s violent nature.

More updates will follow as law enforcement confirms further details in this tragic case.