WINSTON-SALEM, N.C. (AP) _ A trucker suspected in a string of slayings along interstate highways has confessed to a third murder, authorities said.

Sean Patrick Goble had already admitted to suffocating Alice Rebecca Hanes, 36, of Columbus, Ohio, and strangling Brenda Kay Hagy, 45, of Bloomington, Ind., authorities say.

Before his arraignment Monday, Goble confessed to killing an unidentified woman whose body was found Feb. 19 off Interstate 40 in Guilford County, said Sheriff B.J. Barnes.

Goble, 28, of Asheboro, was arrested Thursday in Winston-Salem. Investigators want to question him about dozens of similar slayings in 10 states. Many of the victims were prostitutes who were smothered or strangled and left alongside major highways.

He waived extradition to Tennessee _ where Hanes and Kagy were killed _ during the brief hearing Monday. He also waived his right to an attorney and represented himself, standing with his hands crossed behind his back while District Court Judge Ron Spivey explained the extradition process to him.

At least six uniformed officers surrounded Goble, who was dressed in dark blue coveralls and wore leg chains.

It was not immediately clear if the Guilford County charges would have any effect on the extradition to Tennessee.

Hagy was killed in January at a service station in eastern Tennessee, and her body was dumped along Interstate 81 in Virginia. Hanes was killed at another Tennessee gas station near I-81. Her body was discovered March 19 about 60 miles away, near the highway in Kingsport, Tenn.

Police said they found Goble's fingerprints on a plastic bag near one of the corpses, and blood stains inside his tractor-trailer cab. A search of his mobile home turned up women's undergarments and shoes.

Investigators have refused to discuss a motive for the slayings.

Meanwhile, a newspaper reported today that Goble's father, Kenneth Goble, a former sheriff's deputy in Winnebago County, Ill., twice served time in prison for raping children.

Goble was 6 years old, sitting in his father's car outside the victim's house, during the first attack, reported The Register Star of Rockford, Ill.