Messages that Duncan allegedly wrote in longhand and mailed to another person are being posted on the Internet.

The messages are mostly religious in nature, and do not address the charges that Duncan killed three people outside Coeur d'Alene, Idaho, last year so he could kidnap two small children for sex.

The blogs were revealed this week on a web site called "The Cellar" that is exhaustively dedicated to Duncan.

Jules Hammer, an East Coast blogger who operates The Cellar, refused to identify who is helping Duncan post the messages, saying that person wanted to remain anonymous. She said that person had been helping Duncan since November in hopes that Duncan's writing would provide incriminating evidence.

An FBI agent, speaking to The Associated Press on condition of anonymity, said the agency cannot confirm conclusively that the writings are Duncan's. But agents have been monitoring the new blog and assuming it was Duncan's work.

"There is a real dearth of information about him, anyway," the agent said. "We are certainly going to look at any of his writings, to see if they have any investigative value."

"I want him to write as much as he can," the agent added.

The FBI would have no way to prevent Duncan from mailing letters, the agent said.

Officials for the Kootenai County Jail in Coeur d'Alene, Idaho, where Duncan is being held, could not confirm the blog contained letters written from jail by Duncan.

"We don't know," sheriff's Capt. Ben Wolfinger said Tuesday, even though all mail sent by inmates is read by jail staff.

"All we scan for are contraband requests or escape plans or plans to commit crimes," Wolfinger said. "The rest of it just goes on through."

Duncan is provided two stamped envelopes a week for free to send letters, Wolfinger said.

Duncan's public defender, John Adams, declined to comment.

Hannah McFarland, a handwriting expert from Seattle, analyzed copies of the actual letters Duncan allegedly wrote, provided to her by KXLY-TV of Spokane. She compared those letters to documents known to have been written by Duncan, and said they appeared to be the work of the same person.

"It's a qualified opinion because I didn't have original documents," said McFarland, who worked with Internet files of the documents and a fax, "which distorts writing a little."

But she said nothing in the new letters was different from the known Duncan documents.

Duncan, 42, of Fargo, N.D., has pleaded innocent to three counts of first-degree murder and three counts of first-degree kidnapping in the slayings of three people in a northern Idaho home in May 2005. His trial is set for April 4.

Prosecutors allege Duncan killed Brenda Kay Groene, 40; her son, Slade Vincent Groene, 13; and her boyfriend, Mark Edward McKenzie, 37, in order to abduct and sexually assault Dylan Groene, 9, and Shasta Groene, who was 8 at the time. Shasta was rescued seven weeks later, but Dylan's remains were found in Montana.

Duncan has not been charged with the children's abduction, or with Dylan's slaying. Federal authorities said they will wait until the Idaho charges are resolved before filing those charges.

Duncan is a computer expert who wrote extensive, often unsettling, blogs before his arrest, chronicling his life as a registered sex offender. In his final entry before his arrest, he wrote "My intent is to harm society as much as I can, then die."

His blogs were not updated for months after his July arrest at a Coeur d'Alene Denny's, because he does not have computer access from the jail.

The most recent posting on the blog - called "Blogging the Fifth Nail: Revelations" - is dated Monday, Jan. 23, and is headlined "We Need Tougher Sex Crimes (Uh...laws)"

In it, the writer compared the nation's focus on cracking down on sex crimes with the failed Prohibition effort of the 1920s, which he said expanded organized crime.

"So now we need to get "tough on sex crimes?" the blogger wrote. "That's synonymous to saying, "We need more sex crime!"

The blog said that sex offenders who find themselves under greater public scrutiny because of new laws will only be spurred to commit more crimes to prove they have control of their own lives.

"A very good friend of mine who happens to be a `serial killer' told me that he committed more sex crimes during the two years he was on parole (including killing three children) than he did in the entire five years he was not on parole," the blogger wrote.

In addition to the Idaho charges, Duncan has been identified by authorities as the prime suspect in the killing of a boy in California.

The blogger wrote that his serial killer friend did not commit more crimes until police began checking quarterly at his home.

"So now more people are dead and hurting because some police chief decided to take it upon himself to get tough on sex crime," the blogger wrote.

Before his arrest, Duncan had vehemently complained on his blog about all the attention he was receiving from Fargo police.

Many of the new entries are philosophic ruminations on love, religion and philosophy, and he gives God the name of "William."

On Jan. 2, the blogger wrote about visiting the Seattle Center at the age of 10 and taking carnival rides. Duncan was raised in the Tacoma area.

He also wrote that day that he felt remorse every time he filled a car with gas rather than protesting the war in Iraq, or saw a homeless person and didn't offer them a place to stay.

"I feel remorse for every time I licked a stamp to pay a bill but did not send a letter to someone in prison," he wrote.

"As a matter of fact, I feel remorse for all the times I forgot about God and thought only about myself! So, yes, I do feel remorse. Don't you?"