DOYLESTOWN, Pa. — A judge has convicted a Florida man of third-degree murder in the slaying of a 14-year-old Pennsylvania girl more than three decades ago.

Judge Wallace Bateman Jr. also convicted 57-year-old George Shaw of Geneva of attempted indecent assault but acquitted him of rape Monday in the nonjury trial in Bucks County.

Prosecutors alleged that he drugged and suffocated Barbara Rowan in Bensalem in August 1984, then dumped her duct tape-bound body along a highway with the help of a friend.

Fifty-three-year-old Robert Sanders testified against Shaw and is awaiting sentencing on a guilty plea to hindering apprehension.

Defense attorney Louis Busico attacked Sanders’ credibility and what he called “gaping holes” in the case.

Under law in effect in 1984, the maximum term for third-degree murder is 10 to 20 years.