AN INTERNET blog provided a chilling insight into the mind of a sex offender yesterday as he was charged with kidnapping an eight-year-old girl and questioned over the murders of her family.

Joseph E. Duncan III was found eating in a roadside diner with Shasta Groene, who had been missing with her brother Dylan, 9. Six weeks ago, three members of their family were found bound and beaten to death in their Idaho home.

Mr Duncan, 42, kept an anonymous blog in the weeks before the abduction, in which he warned the world that his demons were “taking over”. He had spent much of his life in jail after being convicted of raping a 14-year-old boy at gunpoint in 1980.

Last night, as Mr Duncan was being questioned about the triple murder on May 15 of the girl’s mother, Brenda Groene, 40, her brother Slade, 13, and her mother’s boyfriend, Mark McKenzie, police were studying the blog for clues to a killing and kidnapping case that has repulsed America.

One of the last dramatic blog entries came on May 11, five days before the bodies were found at the family’s rural property. It was headed “The Demons Have Taken Over”.

Mr Duncan, who lived in Fargo, North Dakota, said that he was about to turn murderously violent, writing that his demons “locked up the ‘Happy Joe’ person in the same dungeon that ‘Happy Joe’ kept them for so many years. Now they are loose and I’m very afraid. I am scared, alone and confused, and my reaction is to strike out toward the perceived source of my misery, society. My intent is to harm society as much as I can, then die.”

He said that he was on his knees, crying to God for help.

The website, called the Fifth Nail, was begun by Mr Duncan as a campaign for more compassionate treatment of sex offenders. But it turned sinister in April, after he was charged with a second-degree sexual assault of two boys in a Minnesota school playground.

Police alleged that a year ago Mr Duncan pulled down the trousers of a seven-year- old boy and fondled him while holding a video camera. Soon after paying $15,000 (£8,530) in bail in April, he disappeared.

On April 24, he wrote: “If you are reading this, and you believe in God, please pray for God to help me defeat my demons.” In another entry, he wrote: “I’m afraid, very afraid. If they (my demons) win then a lot of people will be badly hurt, and they’ve had their way before, so I know what they can do.” The last entry, on May 13, two days before the murders, said: “My mother is crying right now, because her son is in trouble again.

She tried to raise a good son, and she knows her son has a good heart, so why does he do these things?” In 1980 Mr Duncan, then aged 16, was convicted in Washington State of raping the 14-year-old boy twice while holding a gun to his head and burning him with cigarettes. He served 14 years in prison.

In July 2000 he moved to Fargo, where he registered as a Level III sex offender, those considered most likely to reoffend.

He enrolled at North Dakota State University to study computer science and became a member of a fraternity for academic excellence.

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