(KRON) -- The Alameda County Sheriff's Office is investigating the in-custody death of an Oakland man as a homicide, authorities said Tuesday. Elias Angel Rivera, 37, was arrested by the California Highway Patrol on May 21, 2022, for murder. He was booked into the Santa Rita Jail’s maximum-securi ty housing unit on that same day, the sheriff’s office said. On Monday, just before midnight, authorities said that deputies at the jail responded to an emergency call button activated by Rivera’s cellmate. Rivera was found visibly injured and unresponsive. Bay Area man facing 100 years in prison Rivera was transported to the hospital, where he succumbed to his injuries at 1:11 a.m. on Tuesday. The county medical examiner will determine the cause of death. The homicide investigation remains ongoing, the sheriff’s office said. ...read more read less