A 21-year-old student from College Park was acquitted of felonious assault but found guilty of trespassing yesterday in a trial that grew out of a bizarre shooting and stabbing incident in the small Loudoun County town of Round Hill last February.

The verdicts in the case of John Schaffer by a Loudoun county Circuit Courty jury came at the end of an emotional three-day trial that pitted youth against age and attracted wide interest outside the largely rural Virginia county.

Schaffer could have been sentenced to 20 years in prison if he had been convicted of the assault charge. The trespassing conviction makes him subject to a fine of up to $1,000. Sentencing was postponed and he will be tried on a related petit larceny charge in October.

The trial pitted Schaffer and John Goode, his classmate at St. Mary's College in Southern Maryland, against 70-year-old Arthur Horning, a white-haried farmer who until the incident was best know to his neighbors for his blueberry bushes.

Schaffer and Goode, who will be tried separately next month, said they were cruising Loudoun in search of abandoned houses when the incident occurred last Feb. 15.

The confrontation between the students and the farmer occurred in Horning's dilapidated 17-room house in the town 65 miles west of Washington. When it was over, Schaffer had been shot four times, Goode had suffered two flesh wounds and Horning was beaten and covered with stab wounds.

During the trial, Shaffer, who testified from a wheelchair, claimed he and Goode thought the house, 100 miles from their campus, was abandoned. They removed a windowpane and scouted the house for what they described as "junk treasure."

Horning countered that while the house needed a few repairs and he had not lived there for at least four months, it was still home to him and contained a lifetime of possessions. So when he saw the windowpane missing while making his daily visit to the house from nearby Bluemont, he said his reaction was emotional. With a .22 caliber pistol he retrieved from his truck, Horning searched the house until he located the students in an upstairs bedroom.

Horning admitted that neither Schaffer nor Goode had made any move toward him when he began firing the first of six shots at them.

"They didn't make no effort to surrender," testified Horning. "They looked like they wanted to leap at me."

Schaffer testifed he was standing against a wall until he was wounded for the third time. Then, after falling to the floor, he said Horning took deliberate aim for a final shot.

"I begged him not to shoot me, then he shot me again," Schaffer as 15 of his friends and family in the courtroom wept.

Horning testified that when the last of the shots was fired, Goode wrestled him to the floor and stabbed him repeatedly. Horning said he never saw a weapon and didn't see Schaffer stb him but claimed more than one person was assaulting him.

Dr. Joseph M. Rogers of Loudoun Memorial Hospital, who treated Horning on the day of the incident, testified that the farmer had multiple stab wounds on his legs, back, chest, and the base of the skull.

Much of the testimony centered on the condition of Horning's house. In a pretrial hearing police described the house as a "junkyard" and said "you could hide an elephant in there."

Marvin Miller, Schaffer's attorney from Alexandria, submitted pictures of the old wooden house that showed it to have peeling paint, broken windows and a few holes in the roof and to be overgrown with weeds.

Horning said his house was just old rather than abandoned. He testified a telephone was hooked up and said the "junk" referred to by the police was furniture collected over a half a century.

After waiting eight hours today for the jury to return its verdicts, Schaffer's family and friends mobbed him in the courtroom. "I think justice was well served," said Fred Schaffer, John's father, who works for the Defense Department.

Horning could not be reached for comment.