Sepulveda swallowed the balloons, which apparently burst. The drugs caused a fatal overdose, according to prison officials.
The balloons were found during the inmate’s autopsy.
"Investigators from CDCR's Bay Area Special Service Unit (SSU) and CMF's Investigative Services Unit (ISU) determined Martinez-Meth visited the inmate shortly before his death," a news release from jail officials said. "Special agents from SSU, CMF's ISU and CDCR's Fugitive Apprehension Team served a search warrant on Aug. 2, 2018, at Martinez-Meth's Clearlake residence and found items including methamphetamine, balloons and glue."
Martinez-Meth was arrested at that time. Investigators worked with prosecutors from the Solano County District Attorney’s Office to secure the felony conviction in Sepulveda’s death.
Jared Lozano, acting warden of the California Medical Facility, praised the cooperative efforts.
"I am proud to work with a team that continues to show an unrelenting commitment to protecting our staff, inmate population and visitors alike," Lozano said in the news release.