Marshawn Kneeland, Cowboys DE Who Died By Suicide, Diagnosed W/ CTE

Marshawn Kneeland, late Cowboys pass rusher who took his life in November, has been diagnosed with chronic traumatic encephalopathy (CTE), according to doctors.

The 24-year-old pass rusher's brain was sent to the center for a posthumous examination after his tragic death from a self-inflicted gunshot wound ... and on Tuesday, doctors at Boston University's CTE Center released their findings, saying Kneeland had Stage 1 CTE.

Stage one is the first stage of the disease, characterized by short-term memory loss, mild aggression and depression, and headaches, according to experts.

“Unfortunately, I was not surprised to find CTE in the brain of Mr. Kneeland, because we have found this progressive brain disease in nearly half of the athletes we’ve studied who have died before the age of 30," BU CTE Center Director Dr. Ann McKee said.

Kneeland saw the field in only 18 NFL games over two seasons, but had played tackle football since he was a seven-year-old child.

“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,” Catalina Mancera, Marshawn's GF, said.

The findings also show that despite an increased effort on player safety, football is still a violent game.

“Mr. Kneeland played in the modern era of concussion protocols and better helmets, and yet he still developed CTE,” Concussion & CTE Foundation CEO Chris Nowinski said.

He added ... “We have no reason to believe the current generation is at a lower risk of CTE than previous generations. Concussion protocols do not prevent CTE, because CTE is caused by repeated head impacts, not just concussions."

Following his November 2025 death, Kneeland was mourned by family, friends, fans, and teammates and coaches around the league, with Cowboys head coach Brian Schottenheimer fighting back tears, describing Marshawn as a "beloved teammate."

Kneeland's CTE diagnosis once again leaves the football world asking hard questions.