Former NFL star Lawrence Phillips was found dead in his prison cell Credit: Joe Robbins/Getty Image

Former NFL star Lawrence Phillips was unresponsive in his prison cell in Kern Valley State Prison outside Bakersfield, California, in the early hours of Wednesday, January 13. He was 40 years old.

According to a press release from the California Department of Corrections and Rehabilitation, authorities are treating the death as a suspected suicide.

Phillips had been living in solitary confinement since he was named as a suspect in the death of his cellmate, 37-year-old Damion Soward, last April. The athlete was charged with first degree murder on September 1 in the death of Soward.

In a letter he wrote to his mother a month before Soward’s death, Phillips noted that his anger and frustration was at a breaking point.

“I feel myself very close to snapping,” he wrote in a letter dated March 5, 2015. “My anger grows daily as I have become fed up with prison. I feel my anger is near bursting and that will result in my death or the death of someone else.”

The late athlete played for several NFL teams, bouncing from the St. Louis Rams to the Miami Dolphins to the San Francisco 49ers before his arrest in August 2005. At the time, he was accused of driving a car into three teenagers and assaulting his girlfriend — choking her on two separate occasions. He was sentenced to 31 years in prison for his crimes.

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