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, a brain abnormality linked to repeated concussions, his family announced Tuesday.
The Boston University CTE Center, which investigates the long-term consequences of repetitive brain trauma in athletes and others, analyzed Kneeland's brain tissue after his death. Researchers determined Kneeland, who was 24, was in stage one of four of CTE.
