SACRAMENTO (AP) – The Sacramento County sheriff says a man suspected of being one of California’s most elusive serial killers is on suicide watch and talking to himself.

Sheriff Scott Jones said Friday that Joseph James DeAngelo was in a psychiatric ward of the county jail and has said little. Jones says there’s been “quiet reflection” and mumbling.

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Jones says investigators are sifting through every item, receipt and piece of paper from DeAngelo’s home. They’re searching for any possible clues to tie him to more than 170 crimes authorities believe he may have committed.

Investigators suspect DeAngelo is the Golden State Killer, responsible for the deaths of at least a dozen people and rapes of 50 women from 1976 to 1986.

Jones declined to discuss the DNA method used to identify DeAngelo.

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However, a genealogical website confirms their database was used to track down the suspected Golden State Killer. But, the company says it had no idea its service was involved in the hunt for one of California’s most elusive serial killers.

GEDmatch said in a statement Friday on its website that it was never contacted by law enforcement or anyone else about the case or the DNA profile that was used.

The Florida-based company pools DNA profiles that people upload and share publicly.

GEDmatch says it has always informed users that its databases can be used for purposes other than genealogical research.

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Copyright 2018 The Associated Press.