TULSA, Okla. (AP) -- A truck driver already convicted in a California killing pleaded guilty Wednesday to first-degree murder in the 1975 slaying of a Tulsa junior college student.


District Judge Gordon D. McAllister Jr. sentenced Clyde Carl Wilkerson to life in prison after the 65-year-old entered his plea in Tulsa County District Court.


Wilkerson will serve the sentence concurrently to the California life sentence he received last year after pleading guilty to killing a man and raping his wife in 1965.


The corrections departments from the two states will determine where he serves his time. Wilkerson will be eligible for parole in California in six years and Oklahoma in 20 years, but neither is likely, his lawyer said.


"He's aware he's going to be spending the rest of his life in custody," said Tonya Guinn, with the Tulsa County public defender's office.


Wilkerson was not eligible for capital punishment or life without parole in Oklahoma because those punishments were not options at the time of his crime. The death penalty was reinstated here in 1977.


Geraldine Martin, 28, was abducted Feb. 5, 1975, from the parking lot of the downtown campus of then-Tulsa Junior College. Her body was found three weeks later in a vacant apartment. She'd been strangled and raped.


Prosecutors charged Wilkerson 11 months ago with Martin's murder after DNA evidence tied him to the crime.


The long-haul trucker became a suspect in the Martin case in November 2002, after police in El Cajon, Calif., notified Tulsa police that they were investigating him.


He was arrested in Arkansas in 2002 after DNA testing tied him to the California case. His DNA also matched DNA obtained from physical evidence in the Martin case, police say.