Ronnie Lee Gardner waited too long to assert certain claims challenging his death sentence and cannot bring them just weeks before his scheduled execution, a lawyer for the state said Friday.

In a motion filed in 3rd District Court, Assistant Utah Attorney General Thomas Brunker asked Judge Robin Reese to reject Gardner's request to stop the execution and hold a new sentencing hearing.

Brunker wrote that deadlines had passed years ago for Gardner to argue that his constitutional rights were violated and that his previous defense lawyers were ineffective because they failed to present adequate mitigating evidence at his 1985 sentencing.

Gardner's other argument -- that it would be cruel and unusual punishment to execute him after 25 years on death row -- also was filed too late, argued Brunker. Besides, he said, that claim is invalid.

"A condemned cannot resort to the careful but prolonged review process that our society's standards of decency demand to assure the constitutional soundness of a death sentence, then complain that the resulting delay itself makes the sentence unconstitutional," Brunker wrote.

A hearing before Reese on Gardner's request for a new sentencing is set for May 27.

Gardner was sentenced to death for murdering attorney Michael Burdell during an April 2, 1985, escape attempt from the now-demolished courthouse in Salt Lake City. After a woman slipped him a gun, Gardner wounded bailiff Nick Kirk and fatally shot Burdell before being captured on the courthouse lawn.

After years of litigation, Reese signed a warrant last month at the request of the Attorney General's Office, which said Gardner had exhausted his appeals. Gardner, who is scheduled to die June 18, chose the firing squad over lethal injection as the execution method.

In addition to the stay request in 3rd District Court, Gardner has asked the state's Board of Pardons and Parole for a commutation hearing, where he would ask that his sentence be reduced to life in prison. He also has an appeal pending at the Utah Supreme Court, which will hear arguments on June 3.