Matthew Musolino III, the 18-year-old Fairfax County youth who will be sentenced Friday on charges connected to the arson that destroyed Fort Hunt High School last winter, and his father, Matthew Musolino, 59, each were acquitted yesterday of separate misdemeanor charges unrelated to the fire.

Musolino III was acquitted by Fairfax General District Court Judge Eugene Morris of using "curse and abuse" against a police officer in an incident involving a barking dog. The elder Musolino was acquitted on a charge of obstruction of justice in the same incident. A third charge against the father of keeping a barking dog in violation of a county noise ordinance was dismissed by the judge.

Defense attorney Mark D. Cummings said he was gratified with the outcome of the case. "The only unfortunate thing is I believe that the Musolinos will continue to be watched by certain elements of the Fairfax County Police, particularly in the Groveton substation," Cummings said. "I hope no future incidents are provoked."

The younger Musolino is to be sentenced Friday on misdemeanor charges of damaging public property in connection with the school fire. Two other youths have been sentenced in connection with the fire. Musolino faces up to a year in jail and a $1,000 fine on the charge.

He was convicted Monday on assault charges and sentenced to 360 days in the county jail in another trial unrelated to the school fire. He has appealed that conviction and was released from jail yesterday on a $2,000 bond pending an appeal hearing on the assault Sept. 20 in Fairfax Circuit Court.

Fairfax County police officer A.S. Thompson testified yesterday that he went to the Musolino home at 2:30 a.m., on June 23 to investigate a neighbor's complaint of a barking dog. There Thompson said, he found the younger Musolino standing next to a dog.

According to the officer, Musolino III shouted at him to "get the hell off my property and stay off," as well as other "abusive" statements.

At that point, Thompson said he returned to his police car to confer via radio with headquarters. When he later returned, he said the elder Musolino had joined his son. According to Thompson, the father also told him to "stay off my property."