The race for commonwealth's attorney is just beginning to be run in store windows and front yards, where the first campaign signs are appearing. But incumbent Robert D. Anderson and Democratic challenger Jerry L. Johnson already have been fighting it out in the courtroom.

In a flurry of court documents and letters to judges filed over the past several months, the candidates for top prosecutor have attacked and counterattacked, each criticizing the other's conduct in the legal arena.

In the back-and-forth, Johnson has accused Anderson of "playing politics" on the job and his assistants of trying cases "by the seat of their pants without any advance preparation." Anderson has said Johnson "does not challenge the policies of the incumbent but rather attacks the incumbent and other members of the office personally."

Loudoun's judges have tried to keep the sparring focused on the case at hand rather than on the campaign. In each instance, the legal issue has been whether Anderson's assistants should be allowed to prosecute defendants represented by Johnson and his partners while the campaign is underway.

"You may not use this forum as a means to express your political views or aspirations," General District Court Judge James Forsyth told Johnson during a hearing Wednesday. The winner of the November election, Forsyth said, "is literally of no interest to the court."

Johnson, 37, a partner at the Leesburg firm of Johnson, Young & Ault, has been publicly critical of Anderson from the moment he joined the race. During his March announcement on the courthouse steps, Johnson said Anderson has "abused the powers of his office and the trust of the citizens of Loudoun County," citing the office's investigation into allegations of misuse of Town of Leesburg credit cards, which resulted in the resignation of the town manager and a Town Council member.

Anderson, 41, a former defense lawyer, responded by saying that his office's record "stands on its own despite mischaracterizations."

The conflict first entered the courtroom when Anderson, in a March 19 memo, notified all judges that his assistant prosecutors would not handle any cases against defendants represented by Johnson and his firm "in an effort to avoid any conflict of interest or the appearance of such a conflict."

In the memo, Anderson said he would seek to have a special prosecutor from a neighboring jurisdiction take those cases. He later revised his position, saying he would handle all cases represented by Johnson and his partners and would seek an outside prosecutor only if he was unavailable.

Anderson said he made that decision after an assistant commonwealth's attorney who prosecuted one of Johnson's clients in traffic court reported becoming uncomfortable when Johnson mentioned the election while negotiating a disposition. Anderson said he believed that the conversation was inappropriate, and he wrote a letter to Johnson noting his concerns.

"It has been reported to me that yesterday during heated negotiations over the disposition of a traffic case . . . you made reference to the Assistant Commonwealth's Attorney that you might become his boss in the future," Anderson wrote in a Dec. 4 letter to Johnson. "Should this behavior occur again, I will take serious steps to insure that no Assistant Commonwealth's Attorney will be threatened with the possibility of losing his or her job as part of any negotiation over a criminal or traffic case."

Johnson wrote back saying that the "gratuitous comment . . . occurred only after our cordial negotiations had ceased. . . . Moreover it contained no explicit or implied threats or references to anyone losing his job, other than obviously you."

The assistant commonwealth's attorney, William R. Fitzpatrick, could not be reached for comment.

In recent weeks, Johnson and Anderson have argued in Juvenile Court and General District Court over whether Johnson and his partners should be required to notify the court when they are hired to represent a defendant, giving Anderson time to find a special prosecutor if necessary.

Anderson argued that such notice would allow him to determine whether a special prosecutor was needed and would allow the court dockets to move more quickly. Johnson said he doesn't oppose bringing in an outside prosecutor but does worry that Anderson's request for notification is simply a means to scout out the facts of the cases and gain time for extra preparation.

"It has become patently clear to our firm that Mr. Anderson wishes to pick and choose for political convenience which cases he will try personally against our firm and which ones he will seek the appointment of a special prosecutor," Johnson wrote in a May 27 motion. "It is clear [that Anderson] has no intention of engaging in meaningful plea discussions with members of our firm and will force us to trial on cases that any third-year law student could win due to overwhelming evidence and conveniently not be available for more challenging cases, all for the political goal of running up a win record against our firm."

On Wednesday, Forsyth urged Johnson to provide notice when his firm is hired to represent a defendant and said he likely would approve a prosecution request for a delay if that notice was not given. Anderson and Johnson said a Juvenile Court judge ruled that each request for a delay would be decided individually.

Several local lawyers said the courtroom clash that has developed since Johnson's announcement is unprecedented. Although they say it is proper to argue in court whether a special prosecutor is necessary in any given case, some said the arguments seem to go beyond the legal realm into the political arena.

"I don't think that the judicial system is enhanced by having politics as part of its normal process," said Leesburg lawyer Peter C. Burnett, president-elect of the Loudoun County Bar Association. "Both candidates need to find a way to get the political issues out of the courtroom."