Not even Utah's territorial prosecutors executed a man for assaulting a guard or inmate while in prison. In fact, no one in the United States has ever received the death penalty for such a crime.

State prosecutors want to break that historical jur-is-pru-dence.They argued before the Utah Supreme Court on Tuesday that a rarely used state law allowing death for such an act is not only constitutional but also the will of the people.

The high court took arguments under advisement in the unrelated cases of Gary W. Simmons and death row inmate Ronnie Lee Gardner. The two men are the first in Utah charged under the statute and could be executed if convicted.

The provision has been part of Utah code in one form or another for almost 100 years.

Its current language, updated in 1973, says that a prisoner serving a sentence for a first-degree felony can be executed if he or she commits aggravated assault while in lockup.

Defense attorneys call the statute "stale and anachronistic." Specifically, it violates the U.S. and state constitutions and is cruel and unusual punishment, said Simmons' attorney, Fred Metos.

He and Gardner's attorney, Ron Yengich, asked the justices to strike it down, ruling it unconstitutional on its face.

"Have our standards of decency evolved to the point where we need to impose the death penalty for assault in prison?" he asked. "Unless there is a death . . . it is clear from (case law) that the death penalty would be inappropriate."

Utah is one of only three states with statutes allowing execution for the crime of assault by a prisoner. Colorado and California both require that the assault result in death before a prisoner can be led to the execution chamber, unlike Utah's law.

Montana's statute contains no such distinction, but prosecutors there have never pushed for death in such a case, Metos said.

Yengich argued in briefs filed with the court that the U.S. Supreme Court also has ruled on several occasions that death for a criminal who didn't kill or "participate recklessly" in someone's death is unconstitutional.

"Only in the most extreme crimes is the death penalty allowed. In Utah, a person can commit murder while in prison and still not get executed, but they can if they assault someone. What kind of sense does that make?" Yengich said.

Carol Clawson, solicitor general for the Utah Attorney General's Office, responded that the law is a necessary deterrent in a violent prison system. It also is the will of the Legislature, the people's representatives.

"First, the statute applies in a unique environment - a prison, where the threat of escalating violence is ever-present," Clawson said. "A life-threatening injury is a heinous crime. The death penalty is not reserved only for those who commit homicide."

She pointed to a societal trend toward the death penalty for criminals who don't kill, specifically mentioning a recent federal law allowing the execution of convicted drug traffickers.

She acknowledged none of the new laws allowing execution for non-homicidal crimes have been tested in the courts. However, she believes the U.S. Supreme Court will eventually uphold them.

Utah justices alluded to that position frequently during Clawson's arguments Tuesday, noting they were in no position to "get ahead" or decide the Gardner and Simmons cases based on what the U.S. Supreme Court might do.

Chief Justice Michael D. Zimmerman and Justice Christine M. Durham also repeatedly raised concerns about whether all first-degree felons - including those jailed for nonviolent crimes - could be charged under the law.

"You don't have to be violent to be convicted of a first-degree felony," Zimmerman said.

Gardner, who is already on death row for killing an attorney in 1985 at a downtown courthouse, is accused of stabbing a fellow inmate with a hand-crafted shank in 1994. Simmons is charged with severely beating a guard in the Iron County Jail.

Both victims have since recovered from their wounds.

Local prosecutors said they charged Gardner and Simmons under the old law because of their violent pasts. About 50 other prisoners who have committed similar assaults and who have relatively peaceful criminal histories have been charged with only second-degree felonies.

Justices will probably rule on the issue in several months. Clawson said she may appeal the case to the U.S. Supreme Court if the ruling strikes down Utah's law.