CHICO (AP) — Authorities in Butte County on Monday announced they have arrested a man in the killing of his girlfriend, who disappeared nearly 30 years ago.

Butte Co. homicide victim Tracy Zandstra

Butte County homicide victim Tracy Zandstra (Butte County Sheriff’s Department)

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The Butte County Sherriff’s Office said it arrested 55-year-old Richard Pyle last week in Stockton in the killing of Tracy Zandstra, who was living with him in Stirling City when she vanished in 1991.

The sheriff’s department said that while the body of the 29-year-old woman was never found, detectives have evidence showing she was killed and her body disposed of.

Butte Co. homicide suspect Richard Pyle

Butte County homicide suspect Richard Pyle (Butte County Sheriff’s Department)

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Officials wouldn’t discuss the evidence that led them to Pyle, who was living as a transient in Stockton.

Last week, Pyle was booked into Butte County Jail. His bail was set at $1,000,000. He was scheduled to be arraigned Monday afternoon.

“I am proud of the persistent determination of the many detectives and investigators who have worked throughout the years to bring justice to Tracy and closure to her family,” said Butte County Sheriff Kory Honea.

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It was not immediately known if Pyle has an attorney.