Former Cowboys DE Marshawn Kneeland had CTE when he died at 24

Former Dallas Cowboys defensive end Marshawn Kneeland was posthumously diagnosed with early stage chronic traumatic encephalopathy (CTE) after he died by suicide in November 2025 at age 24. Researchers at Boston University's CTE Center found stage 1 CTE in his brain tissue, a degenerative condition linked to repeated head trauma in contact sports. His family made the diagnosis public in July 2026 to raise awareness about brain injuries among young athletes.

Kneeland was in his second season with the Cowboys when he died following a high-speed police chase in Texas. The news adds a sobering medical dimension to a tragedy that stunned the NFL and deepened ongoing debates about player safety.

Key Takeaways

• Kneeland, 24, was diagnosed with stage 1 CTE, the earliest of four severity stages, after his death in November 2025.
• Boston University's CTE Center analyzed his brain tissue; CTE can only be confirmed posthumously.
• He died by suicide after a police pursuit; people close to him had received goodbye messages beforehand.
• His family released the findings publicly to highlight risks faced by NFL and other high-contact sport athletes.
• Kneeland was a 2024 second-round draft pick who began playing tackle football at age seven.

What did researchers find in Marshawn Kneeland's brain?

Researchers at the Boston University CTE Center determined that Kneeland had stage 1 CTE, the mildest classification on a scale of one to four. CTE is a progressive brain disease associated with repetitive head impacts and has been documented in football players, combat veterans, and others exposed to repeated trauma.

The condition can contribute to mood changes, impulsive behavior, depression, and cognitive difficulties, though symptoms vary. Because CTE cannot be diagnosed in living patients, the finding required analysis of Kneeland's donated brain tissue after his death.

How did the former Dallas Cowboys player die?

Texas authorities found Kneeland's body in early November 2025 after he evaded police during a traffic stop and high-speed pursuit. He crashed his vehicle and fled on foot before dying of an apparent self-inflicted gunshot wound.

Dispatchers told officers that acquaintances had received messages from Kneeland indicating he might be suicidal. The episode unfolded in the Dallas area and drew widespread attention across the NFL.

Why is his family sharing the CTE diagnosis now?

Kneeland's family said the diagnosis does not lessen the tragedy but offers context for struggles he may have faced. They hope sharing it helps the public understand what some NFL athletes experience and encourages broader awareness of brain injury risks.

Experts noted that Kneeland's case emerged despite modern concussion protocols and improved safety equipment, underscoring how early repetitive trauma can still matter. For more on athlete health developments, see our Celebrity Breaking News coverage.

What does this mean for the NFL and player safety?

Kneeland started tackle football at age seven, played at Western Michigan University, and joined the Cowboys as a second-round pick in 2024. His diagnosis at 24 joins a growing list of young players found to have CTE after death, intensifying scrutiny of contact sports at every level.

The Guardian reported that researchers have identified CTE in many athletes who died before age 30. The league and medical community face renewed pressure to balance the sport's appeal with long-term neurological health.