Dallas Cowboys star Marshawn Kneeland’s cause of death aged 24 revealed

The cause of death for former Dallas Cowboys player Marshawn Kneeland has been revealed after he died aged 24 in November.

The defensive end died on Wednesday 5 November 2025 and it has now been revealed that he had been diagnosed with stage 1 chronic traumatic encephalopathy (CTE).

NFL star Marshawn Kneeland died last November

Eight months on from his tragic death, the Concussion and CTE Foundation announced that he had been diagnosed with early CTE following post mortem brain analysis.

In addition to this, the organization confirmed that he had died by suicide.

“Mr. Kneeland played in the modern era of concussion protocols and better helmets, and yet he still developed CTE."

After the announcement, Kneeland’s girlfriend Catalina Mancera and Kneeland’s family released a statement of their own, discussing the ongoing issue of traumatic brain injury in the NFL and beyond.

"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.

“Raising awareness is important to us.

“We continue to remember Marshawn with compassion for the person he was, rather than defining him by the final moments of his life. One Love."

Marshawn Kneeland took his own life at the age of 24. Credit: Cooper Neill/Getty Images

Despite these findings, the CTE Center put out a warning to observers that this discovery does not mean that a post mortem CTE diagnosis should be considered the cause of his suicide.

There are many issues at play, and it had been noted in the past that Kneeland had struggled with his mental health.

In 2020 when he was at Western Michigan there were concerns raised, and at one stage he was required to hand over a firearm to police until notice from a counselor.

Another incident saw police called by a friend to check on Kneeland’s wellbeing.

He was hospitalized after being found on railway tracks claiming he wanted a train to hit him.

Kneeland was discovered by police after his death

Police in Texas found Kneeland dead on November 6th after he had eluded officers during a traffic chase.

He crashed his car and ran away, and police were then later informed that Kneeland had expressed ‘suicidal ideations’.

Brain injury and CTE are a huge issue in sport, but particularly in the NFL, and more research must be done to work out how to keep athletes safe.

Adding to her statement, Dr McKee said: "Thanks to the generosity of our brain donor families, we now better understand the earliest stages of CTE, and it is bringing us closer than ever to diagnosing it during life.

“My team and I are fully dedicated to finding effective treatments and a cure for CTE."