A former NFL player's family has announced that he had a brain abnormality linked to repeated concussions. Marshawn Kneeland, a former defensive end for the Dallas Cowboys, died in November 2025. His death occurred after a high-speed chase with police, and it was ruled a suicide.

The brain abnormality, known as chronic traumatic encephalopathy, was found to be in its early stage. The diagnosis was made by the Boston University CTE Center.

Further details about Kneeland's case are available from the Boston University CTE Center and other sources, including KPRC 2 Houston.