Lawrence Phillips, a former NFL running back, was found dead Wednesday morning, reports People. He was 40 years old.
The footballer was serving a sentence at California's Kern Valley State Prison. Staff discovered his unresponsive body in his cell just after midnight, and transported him to a hospital where he was pronounced dead.
Prison officials are calling his death a suspected suicide.
Phillips, who played for the St. Louis Rams, Miami Dolphins and San Francisco 49ers, was serving a concurrent 31-year-sentence for choking a former girlfriend on two occasions and for driving into a group of teens following a dispute.
He was also set to go on trial in the death of his cellmate, Damion Soward, who was serving a murder sentence. Soward was found choked to death in April 2015.
Phillips may have faced the death penalty if convicted of Soward’s murder.