LOS ANGELES – Lawrence Phillips, a former National Football League player, was found dead in his California prison cell early on Wednesday of a suspected suicide, officials said.

The 40-year-old Phillips was found unresponsive at Kern Valley State Prison and rushed to a hospital where he was pronounced dead, the California Department of Corrections and Rehabilitation said in a statement.

Phillips faced a first-degree murder charge in the strangulation death of his cellmate at the prison. He previously was sentenced to 31 years after being convicted of inflicting great bodily injury in a domestic violence case.

Phillips was once one of the nation’s top college football players at Nebraska. He played for the St. Louis Rams, Miami Dolphins and San Francisco 49ers during a three-year NFL career.