After issuing a controversial acquittal in the case of a South Hills oral surgeon accused of molesting his patients, Allegheny County Judge Anthony M. Mariani was escorted home by a sheriff's deputy and his home was guarded last night.

Chief Deputy Sheriff Joseph Rizzo said that there were no specific threats reported against Judge Mariani yesterday, and the night was uneventful.

Judge Mariani yesterday found Dr. Robert J. Boyda Jr., 44, of Mt. Lebanon, not guilty on all counts after 17 women testified that he had sexually assaulted them while they were under anesthesia.

Judge Mariani, who presided over a nonjury trial, said he believed the women thought they were assaulted. But the fact that they were on a strong cocktail of drugs -- one of which, propofol, has been known to cause sexual hallucinations in rare cases -- made their observations unreliable, the judge ruled.

Last month, Judge Mariani received a letter which claimed to be from 500 former dental and post-graduate students who attended Northwestern University with Dr. Boyda while he was in dental school. The letter claimed that Dr. Boyda had been known for similar behavior years ago.

"If he is found anything other than guilty, our problem will not be with Dr. Boyda Jr., but rather with YOU, and we are prepared to do what would be appropriate in our group consensus opinion at that time," it read. "For now, know that we are all watching and awaiting your decision. If it is as it should be, we will have no further contact, if not, well enough for now."

Judge Mariani said he considered the letter a threat and offered to recuse himself, but Deputy District Attorney Janet Necessary and defense attorney William H. Difenderfer declined.

Judge Mariani today denied reports in other news media that he had been threatened again.

"There was not even an event that occurred that could be misinterpreted as a second threat," he said.

He said that the extra security was a mutual decision between him and the sheriff's department.

When asked directly if he felt threatened, Judge Mariani responded, "You can't ignore the efforts made," referring to the letter, which was sent to both the courthouse and his law office.

One deputy worked a 4 p.m. to midnight shift, giving the judge a ride home and monitoring his house from outside. Another deputy watched the house from midnight to 8 a.m.

Chief Rizzo said no further special protection for the judge is planned. Judge Mariani was back in the courthouse this morning hearing cases.

"It's not uncommon for us to do this," Chief Rizzo said. "If the judge feels uncomfortable, we [provide security]."