A convicted child molester was found dead inside his cell on Tuesday at San Quentin state prison in Marin County. Inmate Mark Squires’ death is being investigated as a homicide, California Department of Corrections and Rehabilitation officials said.

Investigators placed Squires’ cellmate Gustavo Lopez, 36, into restricted housing. The prison’s investigation unit and the Marin County District Attorney’s Office will review the incident. Squires’ cause of death will be determined by Marin County coroners.

Prison staffers responded to an alarm at 3:30 p.m. and went to a cell at the San Quentin Rehabilitation Center, where they found Mark Squires, 70, unresponsive and called for medical assistance and first responders, officials with the California Department of Corrections and Rehabilitation said.

Another homicide occurred at San Quentin in April. James Healy, 43, was allegedly killed by his cellmate, Joshua Jones, 50, CDCR told KTVU. Prison officials announced the development less than two weeks after KTVU published a story saying Healy's family had not been given hardly any details about his death.

The death of a man at San Quentin Rehabilitation Center this week is being investigated as a homicide, officials said Wednesday. Correctional officers at the Marin County facility responded to the cell of incarcerated individuals Mark Squires and Gustavo Lopez at 3:30 p.