CARLISLE, Pa.—A Pennsylvania man has pleaded guilty to the 1990 stabbing death of a convenience store clerk.

Cumberland County District Attorney Dave Freed says that 53-year-old Troy Eugene Klingensmith pleaded guilty Friday to third-degree murder and false imprisonment in the killing of Raquel Westfall.

Klingensmith was sentenced to the maximum penalty of 10 to 20 years for the murder and one to two years for false imprisonment. Freed says Klingensmith will begin serving the sentences in 2017, at the end of his current state prison sentence for other charges.

The 37-year-old Westfall was found in a field in May 1990 after she was abducted while working the night shift at a store.

Her murder was unsolved until Klingensmith was charged in 2008 based on DNA evidence.