Duncan is being held without bail in the Kootenai County Jail in Coeur d'Alene, Idaho, where he faces a murder trial in the deaths of three people in a crime authorities contend was intended to allow him to kidnap Shasta, now 9, and her brother Dylan, 9, for sex. If convicted, Duncan could face the death penalty.

Shasta was rescued last summer after seven weeks; Dylan's body was later found in Montana.

"God himself appeared between me and Shasta and commanded me to take her home immediately. So I did," Duncan wrote. "I do not know why he did not appear to me sooner, you'll have to take up that question with God."

Kootenai County Jail records show that Duncan received a letter from Jean Reed of Vancouver, Wash., on Jan. 25, which condemned him for his life as a child molester. Reed is a Vancouver organizer for Washington's Initiative 921, which seeks to lock up violent sex offenders for life after conviction on a first offense.

Duncan sent a letter back to her last Tuesday, jail records showed.

"We are floored by it," said Tracy Oetting of Skykomish, Wash., initiative sponsor. She rejected the notion that God told Duncan to return Shasta, noting he was captured after employees at a Coeur d'Alene restaurant delayed him and called police.

The group released the letter as a way to publicize the initiative, Oetting said.

Duncan's public defender, John Adams, was not in his office late Monday and is not listed in the telephone book.

Shasta and Dylan disappeared from the home near Coeur d'Alene where their mother, older brother and their mother's boyfriend were killed in May. In July, Duncan was arrested at a Denny's restaurant as he ate with Shasta. Dylan's body was found a few days later at a remote primitive campsite in Montana where the children had apparently been held.

Duncan has offered no explanation for why he stopped to eat in a town where pictures of Shasta and Dylan had been plastered everywhere since their abduction.

In the letter, Duncan described himself as a remorseful man ready to trade places with his victims.

"If dying, even going to Hell, could erase what has happened I would volunteer in a moment," Duncan wrote. "But it can't even though dying at this point in my life would be easier than facing what I have done."

Duncan argued against life or death sentences for sex offenders.

"If you continue to hate me, even kill me, then you send a message to other sex offenders in this country," Duncan wrote. "You need to honestly ask yourself how that message will affect them the next time they see a vulnerable person.

"Since I surrendered to the authorities of this world God has been speaking with me everyday," Duncan wrote. "(No, I'm not crazy and I'm not "hearing voices" or anything like that.) I know it is God talking to me though, because not even the devil himself could have made me turn myself over to my most feared and hated enemy ('the system')."

He signed the letter "Duncan."

Last week, Duncan's lawyer argued that his client's trial should be pushed back from April to November, to await a U.S. Supreme Court decision on the insanity defense. Adams contends Idaho's ban on insanity as a defense is unconstitutional, and the Supreme Court is set to rule on a similar law in Nevada later this year.

Duncan, 42, a registered sex offender from Fargo, N.D., is scheduled to stand trial April 4 on charges he kidnapped and killed Brenda Kay Groene, 40, her son, Slade Groene, 13, and live-in boyfriend Mark Edward McKenzie, 37. All three were found bound and beaten to death at their home.

Duncan is expected to face federal charges of kidnapping the two children and killing Dylan Groene after the Idaho state case is finished.

Duncan has sent more than 60 letters to family and friends and received more than 100 pieces of mail since he was jailed in July. Some of Duncan's writings from jail have appeared on an Internet Weblog.

The Tacoma, Wash., native spent much of his adult life in prison for raping a boy there. He had lived in Fargo, N.D., since his release from prison in 2000. He faces child-molestation charges in Minnesota.