Convicted murderer Ronald Laf-ferty would have been judged insane if state Supreme Court justices had read transcripts that were previously unavailable, his attorneys say.

Attorney Gary Weight asked justices Monday to review the transcripts from two competency hearings in 1985 and to reverse Lafferty's conviction.But Assistant Attorney General Sandra Sjogren said the transcripts contain nothing new and will not change the court's decision.

The court took the arguments under advisement, saying they want to review the transcripts before making a decision.

Lafferty, 46, originally was judged incompetent to stand trial at a January hearing during which he was cooperative with authorities. He was judged competent, however, after an April hearing in which he was uncooperative, Weight said.

Lafferty, a self-proclaimed prophet, was sentenced to die for the 1984 throat-slashing murders of his sister-in-law and her 15-month-old daughter in American Fork.

Lafferty and his brother, Dan, said the killings were ordered by God. Dan Lafferty was sentenced to life in prison.

Attorneys are unsure why the 550 pages of transcripts were not included with the records the high court considered during an earlier appeal by Lafferty. Justices rejected all of Lafferty's claims in that appeal, including arguments he was incompetent to stand trial.