Shutterstock
Marshawn Kneeland had stage 1 CTE (chronic traumatic encephalopathy) at the time of his death. Researchers at the Boston University CTE Center made the diagnosis, and the former Dallas Cowboys defensive end’s family announced it Tuesday through the Concussion & CTE Foundation.
Kneeland was 24. He died by suicide in November from what police determined was a self-inflicted gunshot wound.
CTE is scored on a scale of 1 to 4. Stage 1 sits at the lowest end – but that doesn’t mean it’s minor.
“Unfortunately, I was not surprised to find CTE in the brain of Mr. Kneeland, because we have found this progressive brain disease in nearly half of the athletes we’ve studied who have died before the age of 30,” said Dr. Ann McKee, director of the Boston University CTE Center and chief of neuropathology for the VA Boston Healthcare System.
Dr. Chris Nowinski, CEO of the Concussion & CTE Foundation, pointed to something that should worry anyone following football’s efforts to make the game safer. Kneeland played under modern concussion protocols. He wore better helmets than players from previous generations. None of it stopped CTE from developing.
“We have no reason to believe the current generation is at a lower risk of CTE than previous generations. Concussion protocols do not prevent CTE, because CTE is caused by repeated head impacts, not just concussions. If we want to reduce CTE risk, we must implement CTE prevention protocols and aggressively reduce the number and strength of head impacts at every level of the game.”
That’s the distinction people often miss. CTE doesn’t come from concussions alone – it’s the accumulation of hits, big and small, over time. A player can pass every concussion protocol in place and still be at risk.
The CTE Society describes stage 1 symptoms as short-term memory problems, depression, aggressive tendencies, explosivity and issues with executive function. Whether Kneeland experienced all of these isn’t something the diagnosis alone can confirm; brain studies like this typically happen after death and can’t fully capture what a person felt while alive.
Dallas took Kneeland in the second round of the 2024 NFL Draft, and he appeared in 18 games for the Cowboys before his death. While police searched for him last fall, his girlfriend, Catalina Mancera, reportedly told them he had a history of mental health struggles.
The Kneeland family released a statement addressing the diagnosis directly, framing it as a way to help others understand what athletes in high-contact sports might be dealing with beneath the surface.
“While this diagnosis does not change the tragedy of his passing, it provides important context about some of the struggles he may have been facing. We share this information to help people understand what NFL and other high contact sport athletes might be struggling with. Raising awareness is important to us. We continue to remember Marshawn with compassion for the person he was, rather than defining him by the final moments of his life. One Love.”
Dallas has kept Kneeland’s memory present all season. Players wore No. 94 decals on the backs of their helmets, and the team handed out blue T-shirts featuring his face for pregame warmups. After a win over the Las Vegas Raiders, defensive lineman Osa Odighizuwa grabbed Kneeland’s jersey off the sideline and carried it into the locker room with him.
Last month brought a different kind of update. Mancera announced she’d given birth to the couple’s son on June 11 – a reminder that Kneeland’s story extends beyond football, beyond even his death, into a family still moving forward without him.
