Marshawn Kneeland, a former defensive end for the Dallas Cowboys, tragically died by suicide in November 2025 after a police chase. Following his death, his family revealed that he had been diagnosed with early stage chronic traumatic encephalopathy (CTE), a brain disease linked to repeated concussions.
The Boston University CTE Center conducted an analysis of Kneeland's brain tissue, which confirmed he was in stage one of four in the progression of CTE. This degenerative brain condition is commonly associated with athletes in high-contact sports, such as football, and has been known to cause symptoms including mood swings, impulsive behavior, and depression.
Understanding CTE and Its Impact on Athletes
Chronic traumatic encephalopathy is a serious condition that can only be diagnosed posthumously. Kneeland's family expressed their desire to raise awareness about the struggles faced by athletes in contact sports, stating, "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." They emphasized the importance of understanding the mental health challenges that athletes endure.
According to a 2021 study by Harvard Medical School and the Boston University CTE Center, NFL players are over four times more likely to develop amyotrophic lateral sclerosis (ALS) than other men. This statistic highlights the urgent need for improved safety protocols in sports.
The Circumstances Surrounding Kneeland's Death
On the day of his death, Kneeland was involved in a high-speed chase with law enforcement after failing to stop for a traffic violation. After crashing his vehicle, he fled on foot. During this time, a dispatcher informed officers that Kneeland had sent a group text to acquaintances, indicating he was suicidal.
