Trading places.

To enhance his "firing line" knowledge of litigation, law professor Scott Matheson Jr. is leaving the bookish sanctity of the ivory tower to return to the earthy realism of the trial court arena.And after seven years of prosecuting some of the toughest criminal cases - incest and child abuse - Karen Knight-Eagan is seeking a brief reprieve from a job she loves and an opportunity to contribute her real-life experiences to the more esoteric world of law school.

The two are exchanging places for a year, beginning July 1, in a unique program intended to enrich the Salt Lake County attorney's office and the University of Utah College of Law.

The exchange was Matheson's idea.

He will take Knight-Eagan's place as a Salt Lake County prosecutor, taking on criminal and civil cases. Knight-Eagan will put aside her case files for a chalkboard as an adjunct law professor.

Before his appointment in 1985 as a U. law professor, Matheson was in the midst of the Washington, D.C., high-profile litigation scene. He was a member of a prestigious law firm.

With a clientele including The Washington Post and Newsweek, Matheson's law practice centered on First Amendment issues.

Matheson left the D.C. fast lane to return to his home in Utah, where both his and his wife's parents live.

While he had extensive courtroom experience in D.C., Matheson has never practiced law inside a Utah courtroom. Having practical courtroom experience is crucial to being an effective teacher, particularly in the areas he teaches - litigation and civil procedure - he said.

"A law teacher in litigation subjects has more credibility if he understands what it is like to argue before a Utah judge," he said.

"I had reached the point in teaching that I had command of the subject matter, but my instinctual understanding from courtroom experience was beginning to fade a bit. That instinct will be sharpened through meeting prosecution challenges."

A year ago, Matheson, son of former Gov. Scott Matheson, was regarded as a potential candidate against Sen. Orrin Hatch, R-Utah. Polls showed him faring well against Hatch and he has been named "the Democratic party's rising star."

But for now, as it was a year ago, his ambitions lie in enhancing his professional law skills, not in seeking political position.

The exchange is the kind of thing the university should be doing, said Matheson. Ideally, the law students will benefit from Knight-Eagan's firing-line expertise and the county attorney's office will be enhanced by Matheson's knowledge of law.

Knight-Eagan's motive for taking a temporary leave centers on her philosophy of public service.

While she has faced many stressful, heart-wrenching and sometimes threatening situations as prosecutor of child abuse cases, she loves her work because she feels she is helping vulnerable victims receive justice and begin putting the trauma of abuse behind them.

Having spent three years teaching trial advocacy part time at the law school, Knight-Eagan realizes the power of drawing on her personal experiences in the courtroom.

Child abuse cases, particularly those involving incest, are extremely challenging.

She recalls an emotionally draining case in 1985 involving an 8-year-old victim. The child's father was charged with several counts of sexual abuse and incest.

It was the first case in Utah testing new statutes that allowed a child to have his or her testimony electronically recorded instead of taking the witness stand before a live jury and the accused perpetrator.

Because of her extreme fear of her father, the 8-year-old could not take the witness stand. Her testimony was videotaped. Her father sat in another room with a telephone and television as she testified. Through his attorney, he was able to question her.

The jury was later shown the videotape.

When the verdict was returned, the child's father was found guilty on all charges. Furious, he threatened to kill Knight-Eagan and her co-counsel, Leslie Lewis.

On the day the man was to be sentenced, he committed suicide.

The man's death still haunts her, but the prosecutor has the satisfaction of believing she was on the right side of the case. The child victim suffered from her father's suicide, but the 8-year-old also seemed to understand she did the right thing.

Knight-Eagan hopes to pass on her affinity for public service to law students.

"Law students seem different now than when I was in school. There are fewer social architects. Financial motivation seems more prevalent. Perhaps my teaching will influence some of them to consider public service law," she said.