Former Cowboys defender Marshawn Kneeland, who died by suicide at 24, found to have early stage CTE

This story discusses suicide. If you or someone you know is having thoughts of suicide, please contact the National Suicide Prevention Lifeline at 988 or 1-800-273-TALK (8255). Former Dallas Cowboys defensive end Marshawn Kneeland, who died by suicide in November 2025 after a high-speed chase with police, was diagnosed with Stage 1 of chronic traumatic encephalopathy (CTE) in a postmortem brain tissue analysis. There are four stages of CTE, with Stage 4 showing the most damage. The Boston Univer