The family of Dallas Cowboys defensive end Marshawn Kneeland revealed Tuesday that he was diagnosed with Stage 1 chronic traumatic encephalopathy (CTE).
Kneeland’s family shared the heartbreaking news eight months after he died by suicide at the age of 24, according to a Concussion & CTE Foundation press release. Following his death, his brain tissue was donated for research through the foundation, according to ABC 8 News. An examination conducted by researchers at the Boston University CTE Center reached the diagnosis.
CTE can only be confirmed after death because it necessitates signs of eroding brain tissue, according to the Mayo Clinic.
INDIANAPOLIS, INDIANA – FEBRUARY 28: Marshawn Kneeland #DL41 of the Western Michigan Broncos speaks to the media during the 2024 NFL Draft Combine at Lucas Oil Stadium on February 28, 2024 in Indianapolis, Indiana. (Photo by Michael Hickey/Getty Images)
Dr. Ann McKee, director of the Boston University CTE Center and chief of neuropathology for the VA Boston Healthcare System, said she was “not surprised to find CTE in the brain of Mr. Kneeland.”
She went on to say, “[W]e have found this progressive brain disease in nearly half of the athletes we’ve studied who have died before the age of 30.”
Dr. Chris Nowinski, CEO of the Concussion & CTE Foundation, raised concern about CTE among athletes. “Mr. Kneeland played in the modern era of concussion protocols and better helmets, and yet he still developed CTE,” he said.
Nowinski asserted, “Concussion protocols do not prevent CTE, because CTE is caused by repeated head impacts, not just concussions.”
ARLINGTON, TX – DECEMBER 22: Marshawn Kneeland #94 of the Dallas Cowboys looks on from the field during an NFL football game against the Tampa Bay Buccaneers at AT&T Stadium on December 22, 2024 in Arlington, Texas. (Photo by Cooper Neill/Getty Images)
Kneeland discovered his passion for football at the tender age of 7, ABC 8 reported. He played at Western Michigan University before the Dallas Cowboys picked him in the 2024 NFL Draft’s second round, and took his own life during his second NFL season.
On the day of his passing, the athlete’s girlfriend told police he sent her a troubling message from him, according to 911 dispatch audio obtained by TMZ. Police said Kneeland was connected to a pursuit, and officers found him suffering from a self-inflicted gunshot wound.
LAS VEGAS, NEVADA – NOVEMBER 17: Osa Odighizuwa #97 of the Dallas Cowboys holds the jersey of Marshawn Kneeland after the game against the Las Vegas Raiders at Allegiant Stadium on November 17, 2025 in Las Vegas, Nevada. (Photo by Candice Ward/Getty Images)
Mancera welcomed their child after the athlete’s tragic passing. She issued a statement to the press Tuesday alongside Kneeland’s family, according to the foundation’s press release.
“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,” the statement said. (RELATED: Devastating 911 Audio Seems To Capture Tragic Moments Before Marshawn Kneeland’s Death)
“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.”
Kneeland’s family closed off their statement by writing, “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.”