The family of former Dallas Cowboys defensive end Marshawn Kneeland announced Tuesday that he had early-stage chronic traumatic encephalopathy (CTE), a degenerative brain disease linked to repetitive head trauma.
The Boston University CTE Center conducted the post-mortem analysis of the 24-year-old's brain and determined he was in stage one of the four stages of CTE.
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Kneeland died by suicide in November 2025 in Austin, Texas, following a high-speed police pursuit that began over a traffic violation.
According to authorities, Kneeland fled a vehicle crash on foot after evading Texas Department of Public Safety troopers.
While searching for him, officers learned from a dispatcher that acquaintances had received a group text message from Kneeland saying goodbye.
The progressive brain disease can only be diagnosed after death and is known to trigger depression, impulsive behavior, and violent mood swings in contact sport athletes and combat veterans.
Kneeland's family, including his girlfriend Catalina Mancera, released a statement through the Concussion and CTE Foundation regarding the findings.
"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," stated the family.
The family expressed their desire to promote understanding of the challenges faced by contact sport athletes who endure repeated impacts.
"Raising awareness is important to us.
