sports
Former Cowboys Player Diagnosed With Stage 1 CTE After Death by Suicide
Researchers at Boston University's CTE Center announced Tuesday that Marshawn Kneeland had stage 1 chronic traumatic encephalopathy when he died by suicide at age 24 in November 2025. The finding came from postmortem brain tissue analysis of the former defensive end.
Jul 7, 12:48 PM·2m read11 sources
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Marshawn Kneeland, a former Dallas Cowboys defensive end, received a postmortem diagnosis of stage 1 chronic traumatic encephalopathy. Researchers at the Boston University CTE Center announced the finding Tuesday after analyzing tissue from the player, who died by suicide at age 24 in November 2025. The center's director, Dr.
Ann McKee, said she was not surprised by the result. "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," McKee stated.
Stage 1 is the mildest of CTE's four stages, with symptoms that can include headaches and loss of attention or concentration.
Kneeland died after a car chase with Texas State Troopers that began over a traffic violation. He crashed, fled on foot, and was later found dead from a self-inflicted gunshot wound. He had been drafted by the Cowboys in the second round of the 2024 NFL Draft and played 18 games for the team, including four starts, during his second season.
Kneeland began playing tackle football at age 7 and later played college football at Western Michigan University. CTE can only be diagnosed after death and results from repeated head impacts. Kneeland's family, including girlfriend Catalina Mancera, issued a statement through the Concussion and CTE Foundation.
"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," the family said. "We share this information to help people understand what NFL and other high-contact sport athletes might be struggling with. " Dr.
Chris Nowinski, co-founder and CEO of the Concussion & CTE Foundation, noted that Kneeland played under modern concussion protocols and with improved helmets. "Mr Kneeland played in the modern era of concussion protocols and better helmets, and yet he still developed CTE," Nowinski said.
