Prosecutors are seeking to disqualify Geoffrey Clark as defense lawyer for a girl charged with murder because of Clark's alleged behavior in another case.

Deputy Weber County Attorney Gary Heward filed the motion to disqualify last week. On Tuesday, 2nd District Judge Parley Baldwin gave Heward an April 3 deadline for filing more documentation. Clark then has a week to respond before oral arguments are scheduled.Aletha Austin, 16, faces a murder charge in the July 25, 1996, killing of a North Ogden man by her brother and a friend, both of whom are serving life prison terms for their part.

Austin's case was just returned to 2nd District Court after an unsuccessful appeal by Clark to block her trial as an adult. She was 14 at the time of the killing.

Heward's motion contains a copy of a letter that another Clark client, Trev Poulson, sent to Judge Michael Glasmann last month. The letter claims Clark told Poulson to lie at the trial.

The judge sent the letter to the Utah State Bar association.

The bar is reviewing the letter at the same time it is watching for the outcome of a misdemeanor assault charge filed against Clark for allegedly striking a client, serial rapist Jason Brett Higgins.

Both Higgins and Poulson have said they lied to authorities at Clark's suggestion, which Clark has denied. Subornation, or recruiting of perjury, is a second-degree felony.

"One's a would-be firebomber and the other a serial rapist," Clark said of his accusers. "You have to consider the source."

In a little more than two years in Weber County, Clark has established a high-profile defense practice. Two weeks ago, he signed a one-year lease for a huge billboard describing his "aggressive" law practice.

Poulson, an animal-rights activist, was sentenced to three months in jail last week for pouring 25 gallons of gasoline around the grounds of Montgomery Fur Co. last year. He did not light it.

In his letter, Poulson said Clark advised him they could win the case at trial if Poulson could "conjure up a story and stick with it, and never tell anyone the truth."

Poulson alleges Clark also said they'd both benefit from publicity with a win in the case - Clark in particular for a vendetta Poulson claims the lawyer has for prosecutor Heward.

"He said numerous times, `Let's win this thing so we can shove this down Gary's throat and show the rest of the (prosecutors) I can win anything,"' according to Poulson.

The 19-year-old Poulson also said in the letter that Clark chided him after his conviction, saying witnesses he had instructed in the past to lie "had done a much better job. . . . I didn't want to lie but I figured my lawyer knew what he was talking about."