COEUR D'ALENE, Idaho - A judge on Thursday granted a delay in the triple murder trial of Joseph Edward Duncan III, saying he didn't want to try the case twice in case Idaho's ban on the insanity defense is overturned.

First District Judge Fred Gibler heard nearly two hours of testimony in his chambers before vacating a scheduled April 4 trial date and setting an Oct. 16 start. Gibler said that would give Duncan's lawyers time to prepare for the capital trial, as well as clarify whether Idaho's ban on the insanity defense is constitutional.

"No one wants to try this twice, including me," Gibler said.

Lawyers for Duncan asked that the trial date be moved to November, to give them extra time to prepare a defense for their client, who faces the death penalty if convicted of three slayings near Coeur d'Alene, Idaho, last year.

Kootenai County Prosecutor Bill Douglas argued Duncan's lawyers have already received one delay and should not be granted another.

Idaho law requires the court to "minimize the length of time the child must endure the stress of his or her involvement in the proceedings," Douglas wrote in a motion filed Tuesday.

Lawyers representing Shasta Groene and her family testified in the closed-door session, which Gibler characterized as an expression of the family's wish to get the trial over quickly. Shasta is the sole survivor of the carnage at her home last May 16.

Duncan is being held without bail in the Kootenai County jail on charges of killing her mother, older brother and mother's boyfriend in an act that authorities said was intended to allow Duncan to kidnap Shasta and brother Dylan Groene, 9, for sex. Shasta was recovered alive seven weeks later, but Dylan was killed.

Duncan's arrest last July and the revelations that he had a long history of preying on children for sex have prompted calls in the legislatures of Washington, Idaho and other states to get tougher on sex predators. Washington voters will also consider an initiative this year that seeks to lock up violent sex offenders for life after a first conviction.

Duncan's lawyers want the trial pushed back in part to wait for a U.S. Supreme Court decision on the insanity defense. Public defender John Adams has asked Gibler to rule that Idaho's ban on insanity as a defense is unconstitutional.

The U.S. Supreme Court is expected to rule on a similar law in Nevada this summer.

In November, Gibler granted a request by Adams to postpone the original trial date of Jan. 16.

Duncan, 42, a registered sex offender from Fargo, N.D., is charged with kidnapping and killing Brenda Kay Groene, 40, her son, Slade Groene, 13, and live-in boyfriend Mark Edward McKenzie, 37.

If convicted on any of the six counts, Duncan could face a death sentence.

Duncan has allegedly been sending letters from the jail to supporters and opponents. Some of those have been posted on the Internet.

In a recent letter, Duncan said God ordered him to return Shasta Groene last July, and described himself as a remorseful man ready to trade places with his victims. He also argued against life or death sentences for sex offenders.

Asked if release of the letters could taint a jury pool, Douglas said he did not think so.

"We'll ensure that a fair and impartial jury is selected," Douglas said.