Former Dallas Cowboys defensive end Marshawn Kneeland, who died by suicide in November 2025 after a high-speed chase with police, had early stage chronic traumatic encephalopathy (CTE), a brain abnormality linked to repeated head trauma, his family announced Tuesday.
CTE Diagnosis
The Boston University CTE Center analyzed Kneeland’s brain tissue after his death and determined he was in stage one of four of CTE. CTE is a degenerative brain disease that has been found in athletes in contact sports, combat veterans, and others who experience repetitive blows to the head.
Kneeland’s family, including his girlfriend, Catalina Mancera, said in a statement, ‘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.’
Dr. Chris Nowinski, CEO of the Concussion & CTE Foundation, noted that Kneeland’s diagnosis comes even amid a modern era of concussion protocols in professional and college athletics and better safety equipment. Nowinski said, ‘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.’
Original reporting: Texarkana Gazette — read the source article.
