West Virginia Circuit Judge Pierre Dostert was found guilty in his own Charles Town courtroom yesterday of assaulting a Harpers Ferry-area artist more than two years ago during a late night incident that has become known as the "Copter Caper."

Dostert, a 47-year-old former Washington lawyer known in West Virginia's Eastern Panhandle as a feisty jurist, was fined $100 for the misdemeanor offense of throwing coffee on Audrey Preissler in March 1979.

Preissler and her husband had refused to allow the judge and local police officers to enter their house without a warrant to arrest a helicopter pilot who was their guest.

Three other misdemeanor charges against Dostert stemming from the incident were dropped yesterday after Dostert agreed to plead no contest to assault. Conviction on one of those charges, possession of an unlicensed firearm, carried an automatic six-month jail term.

Dostert, who last year was suspended from the bench for six months as a result of a judicial inquiry into the incident, claimed he had been "literally forced" into the plea bargaining. He claimed the charges against him were "products of one or more deranged minds."

Audrey Preissler, a painter and art gallery owner in the town of Bolivar, near Harpers Ferry, called the agreement "a joke" and said she, too, was upset by it.

"I'm not satisfied and I feel insulted . . . ," said Preissler. "With that man free to sit on the bench again, I suppose we must sell and leave here."

Dostert was elected to the Jefferson County Circuit Court seat five years ago and presides in the historic courthouse where John Brown was convicted and sentenced to hang for leading a slave uprising in 1859.

The Copter Caper has been a source of political mudslinging and local gossip since Dostert, wearing a trench coat over his pajamas, barged into the Preissler home looking for the pilot who had landed his helicopter in a nearby field. When asked for a warrant, according to witnesses, the judge held up a revolver.

"This is America. I am the law and this is my warrant," witnesses claim the judge announced as he pointed his gun at the homeowners. Detlev Preissler was handcuffed and taken to jail where he was charged with obstructing justice. That charge later was dismissed.

Audrey Preissler testified that after her husband had been taken away, she offered the judge a cup of coffee which he knocked from her hand, splashing her.

Yesterday's trial was scheduled after another trial in April was halted when Dostert complained he was having a heart attack. He was rushed from the courtroom and taken by ambulance to a nearby hospital. While bedridden, Dostert signed a court order removing the two prosecutors and the presiding judge from his case.