This photo provided by the Anaheim Police Department shows Itzcoatl Ocampo. Investigators are "extremely confident" that Ocampo was responsible for all four recent killings of homeless men in Orange County.
The autopsy report on a suspected Orange County serial killer has come back inconclusive as to the cause of his death.
Itzcoatl Ocampo, 25, was found shaking and vomiting in his cell Wednesday and was taken to the hospital by Orange County paramedics, where he was pronounced dead.
Orange County Sheriff's Lt. Jeff Hallock told KPCC the investigation will go to the toxicology lab, where tests could take eight to 12 weeks .
Ocampo's lawyer has said he was told his client had ingested cleaning product, the Associated Press reports, but sheriff's officials couldn't confirm that.
"I can tell you that typically we do provide cleaning products to inmates upon their request in small quantity," Hallock told KPCC, "but that's as a way of providing them the ability to keep their housing area clean. But in terms of commenting specifically on Ocampo or his cell, I can't comment because it's an ongoing investigation. "
A former marine and veteran of the Iraq War, Ocampo was scheduled to return to court in January 2014 . He was charged in the murder of six people, including four homeless men who were brutally stabbed near the Santa Ana River trail.