Leticia Willoughby was found unresponsive early Saturday morning after Merced police booked her into John Latorraca Correctional Facility overnight on drug violations and a gang enhancement.
The Merced County Sheriff's Department says Willoughby was checked out by medical staff after she complained of chills and then told staff she wanted to rest.
She was later found dead in her cell. Investigators are waiting for autopsy results to determine what caused her death.
