An Alexandria prosecutor said yesterday that she will not try former Fairfax County principal Anthony M. Rizzo Jr. for a third time on charges that he molested a child 15 years ago, but the chief prosecutor in Orange County, Va., said he is now considering seeking an indictment against Rizzo.

Timothy Sanner, the commonwealth's attorney for Orange County, where some of the alleged offenses occurred, said he plans to review the two trials held in Alexandria Circuit Court, which both ended in mistrials after jurors could not reach unanimous verdicts.

"We're obviously going to have to look at what transpired in Alexandria and see if there is something that could be handled differently here," Sanner said. "It is conceivable we will take some action."

Alexandria Assistant Commonwealth's Attorney Molly Frio said she decided to dismiss the four felony charges against Rizzo, 62, because she would be unable to give a third jury any more evidence than she had given the first two. It was a difficult case for both juries, Frio said. She said she could not bolster the alleged victim's testimony with any physical evidence because the woman, now 24, went to police so many years after the events in question.

"The prosecutor was a fair and decent adversary, and I appreciate her decision to abandon the prosecution," said Rodney Leffler, Rizzo's attorney. "Although Mr. Rizzo and his family will be terribly disappointed if the Orange County prosecutor moves against him, we will deal with that when and if it happens."

Rizzo's accuser said he raped and sexually assaulted her "hundreds" of times over a period of four years, beginning when she was about 10. She did not go to police sooner, she testified, because she was worried about the effect it would have on her mother, who was suffering from a liver disease.

At the time the alleged abuse occurred, her mother was dating Rizzo, who was assistant principal of Edison High School and her mother's supervisor. The alleged abuse occurred at Rizzo's farm in Orange County and at his home in Alexandria, as well as at the mother's residence.

Because of a prior court ruling, Frio was not allowed to tell either jury that Rizzo, who later became principal at Edison, was fired from that job for sexually harassing teachers at the school.

Nor could Frio tell jurors that Rizzo later claimed to suffer from a sexual disorder that made him unable to supervise women without trying to coerce them into having sex with him. Although state retirement officials rejected his claim for a disability pension based on that diagnosis, the Virginia Supreme Court ordered them to pay him disability benefits of about $38,000 a year, saying they had missed a deadline for making a decision in his case.

An Alexandria judge ruled that it would be prejudicial to bring up Rizzo's dismissal and pension claim during the criminal trial. After the second mistrial, several jurors from both panels said that they should have been told about Rizzo's past and that it might have changed their verdicts to guilty.

Sandy Hein, the lead Alexandria police detective in the case, said she and Rizzo's accuser will be meeting with sheriff's deputies and the prosecutor in Orange County.

"I completely believe her," Hein said of Rizzo's accuser. "I feel sorry for all she's gone through, and I believe she deserves to reach a point where she's at peace with the outcome."

CAPTION: Former principal Anthony M. Rizzo Jr. has been tried twice on charges that he molested a child 15 years ago.