Former Dallas Cowboys defensive end Marshawn Kneeland was found to have stage 1 of the degenerative brain disease CTE after a posthumous exam by Boston University researchers.

The 24-year-old Kneeland died of a self-inflicted gunshot wound in November a few miles from the team’s facility in Frisco.

Kneeland’s family, in a statement Tuesday issued by the Concussion and CTE Foundation, said the diagnosis provided clarity on his death:

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

CTE, or chronic traumatic encephalopathy, is a degenerative disease that kills nerve cells in the brain and has been linked to repeated head injuries like concussions. The diagnosis can only be confirmed after death and has been found in several former players, including Junior Seau, Chris Henry and Jovan Belcher.

The CTE Society said stage 1 of the disease is “most commonly marked by headaches, and loss of attention and concentration. Some individuals experience short-term memory problems, depression, aggressive tendencies, explosivity, and executive function issues.”

Chris Nowinski, founder of the Concussion and CTE Foundation, said in a statement that the CTE crisis in the NFL continues.

“Mr. Kneeland played in the modern era of concussion protocols and better helmets, and yet he still developed CTE. 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. If we want to reduce CTE risk, we must implement CTE prevention protocols and aggressively reduce the number and strength of head impacts at every level of the game.”

Kneeland left behind a girlfriend, Catalina Mancera, and a son, Makhai, who was born in June after Kneeland’s death.

Lawrence Dow

Fort Worth Star-Telegram

Lawrence Dow is a digital sports reporter from Philadelphia. He graduated with a master’s degree in journalism from USC. He’s passionate about movies and is always looking for a great book. He covers the Texas Rangers and other sports.