A 45-year-old man died in custody early this morning at the Martinez Detention Facility, Contra Costa County sheriff's officials said.

A correctional deputy conducting room checks at 12:47 a.m. noticed an unresponsive inmate in one of the bunks and called for medical assistance.

Firefighters and an ambulance responded to the scene, but the inmate was pronounced dead. His death appears to be medically related, according to the sheriff's office.

The Contra Costa County District Attorney's Office is investigating the death. According to sheriff's officials, an autopsy will be conducted to try and determine the cause of his death.

The sheriff's office released the man's name via social media Wednesday afternoon, identifying him as James Darryl Cooper of Vallejo. According to officials, he was booked into the Martinez Detention Facility on Jan. 18 on a warrant for domestic violence.

He also had three arrest warrants from Solano County, officials said.