Marshawn Kneeland, the Dallas Cowboys defensive end who died by suicide last November at age 24, was found to have early stage chronic traumatic encephalopathy, according to an analysis of his brain tissue released by his family Tuesday.
The Boston University CTE Center determined that Kneeland was in stage one of four of the degenerative brain disease, which develops from repeated head trauma and can only be diagnosed after death. The finding was announced through the Concussion and CTE Foundation.
Kneeland's death followed a high-speed police chase in Texas. He had fled a vehicle crash on foot after initially evading state troopers over a traffic violation. As officers searched for him, dispatchers learned that Kneeland had sent group text messages to people who knew him saying goodbye, raising immediate concerns about his state of mind. He was later found dead from a self-inflicted gunshot wound.
His family issued a statement emphasizing that while the CTE diagnosis does not explain away the tragedy, it provides insight into potential struggles he faced. "Raising awareness is important to us," they said, adding that they wanted Kneeland remembered for who he was rather than the circumstances of his death.
CTE has been linked to behavioral changes including violent mood swings, impulsive actions, and depression. The condition has appeared in NFL players, hockey and soccer athletes, and combat veterans exposed to repeated brain impacts.
Kneeland began playing tackle football at age 7 and went on to play college football at Western Michigan before being drafted by the Cowboys in the second round in 2024. His case underscores ongoing concerns about long-term brain injury in contact sports even as safety protocols have improved.
Dr Chris Nowinski, CEO of the Concussion and CTE Foundation, said Kneeland's diagnosis demonstrates that modern concussion protocols and equipment have not reduced the underlying risk. "Concussion protocols do not prevent CTE, because CTE is caused by repeated head impacts, not just concussions," Nowinski stated. He called for broader preventive measures across all levels of football to reduce the frequency and force of head impacts.
If you or someone you know is struggling with suicidal thoughts, the National Suicide Prevention Lifeline is available 24/7 at 988 by call or text, or at 988lifeline.org for chat. You can also text HOME to 741741 to reach a crisis counselor.
Author James Rodriguez: "Kneeland's case is a stark reminder that the NFL's safety improvements still don't address the root cause of CTE, and that early-stage brain disease may have been silently contributing to his crisis."
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