Ronald Lee McMinn walked into Alexandria Circuit Court yesterday to be tried on charges of burglary and grand larceny for what police called Old Town's largest theft in recent memory.

But because of a seven-word omission in the prosecution's indictment, Judge Donald H. Kent dismissed the charge of grand larceny against McMinn, even though he said it was clear that McMinn had stolen 18th century Italian paintings, antique clocks and silver valued at more than $200,000 from the home of Elizabeth Schneider at 611 Queen St.

Kent found McMinn, 37, of no known address, guilty of the burglary charge.

McMinn, who was painting and building shelves in Schneider's red brick home when he burglarized it on Nov. 22, 1982, would have faced a maximum of 40 years in prison if convicted of both burglary and grand larceny. He now faces half that time.

"It's distressing that a mistake like this happened," said Assistant Commonwealth's Attorney Randolph J. Myers, who prosecuted the case.

When Myers drew up the indictment in March 1984 he failed to include the words, "of the value over $200 or more" in describing the items McKinn allegedly stole.

"My goodness, the right statute was cited and in the bill of particulars it was clear the value was . . . many times that," Myers said yesterday.

But Kent ruled that by not explicitly stating in the indictment that the stolen valuables were worth more than $200, McMinn could be convicted only of petty larceny. "He can't be convicted of something he wasn't indicted on," the judge said.

Faced with the irony of charging the defendant with petty larceny for a $200,000 theft, Myers asked Kent to dismiss the charge.

"I don't think this will effect the sentence on April 18," Myers said "because in my experience judges usually run burglary and larceny charges concurrently."

Still, Schneider, who now raises white-faced Hereford cattle on a farm in Orange County, Va., said she was "disgusted" that McMinn had not been tried for grand larceny.

McMinn "was a little too curious, too smart for a repairman," she said. "He asked all about the paintings, and I stupidly told him."