Eight-year-old Shasta Groene (search) remembers the smallest details about the night her family was murdered and the six weeks that prosecutors say she spent with a registered sex offender.

According to court records, Shasta remembered the brand of the hammer used to kill her family, the fact that some victims had their feet bound while others did not, and that the killer wore dark gloves. She called her kidnapper "Jet," a nickname Joseph Edward Duncan III (search) used on his disturbingly violent Web journal.

Although child witnesses are sometimes considered unreliable, Shasta's detailed accounts as the sole survivor of the carnage could give prosecutors a powerful tool in their case against Duncan.

Duncan, 42, was arrested when he took Shasta to a Denny's restaurant, and her account closely corroborates physical evidence recovered from the crime scenes and Duncan's stolen vehicle, according to the records.

"I don't think you could have a better witness," said Jim Sweetser, the former prosecutor in adjacent Spokane County (search), Wash.

Shasta's grisly account starts when a stranger broke into her home and killed her family, and she and her brother were taken deep into the forests of western Montana.

For nearly seven weeks Shasta and 9-year-old Dylan endured repeated sexual assaults, according to her account, and at some point Dylan was killed. Dependent on her abductor for survival, investigators said Shasta had little choice but to follow his commands until people at Denny's recognized her from pictures plastered all over town.

Duncan has been charged with three counts of first degree murder and three of first degree kidnapping in the deaths of Shasta's mother Brenda, 13-year-old brother Slade and Mark McKenzie, 37, her mother's boyfriend.

Federal kidnapping and murder charges will be filed later in the abduction of Shasta and the abduction and slaying of Dylan. Most of the charges carry the possibility of the death penalty.

On Saturday, hundreds of people gathered to remember Dylan at a memorial service on what have been his 10th birthday, with a pastor telling mourners: "God is throwing a better party for him than you could ever possibly imagine."

Meanwhile, additional details keep leaking into the open. The Pacific Northwest Inlander, a free weekly based in Spokane, Wash., reported on Thursday that officers had recovered a video camcorder from the stolen Jeep Duncan was driving and found footage of him abusing and threatening to kill the two children. The Inlander also reported that Dylan Groene was shot to death and his body was burned.

The newspaper cited unnamed sources who were working on the case. The FBI and Kootenai County sheriff's office declined to comment on the report.

But Duncan's public defender, John Adams, is incensed about the leaks.

"I thought this was a civilized society and Coeur d'Alene was a city of human rights and not mob rule and trial by press and anonymous sources," Adams complained.

According to statements released this past week, Shasta told investigators that Duncan said he used night vision goggles to case the family's rural house for two or three nights. Night vision goggles were found in Duncan's Jeep, officials said.

Inside the house, Shasta said Duncan wore dark gloves and carried a shoulder-style weapon. Investigators found dark gloves and a 12-gauge shotgun in the Jeep and a red shotgun shell, which Shasta also described, in the house.

Shasta accurately described how her brother and the two adults were bound with zip-ties and duct tape, including that her brother had just his hands bound and the others were bound hand and foot. Detectives said they found an empty zip tie bag in the Jeep.

Although Shasta and her brother were taken to a waiting truck and did not witness the killings of her family, she said Duncan later showed her a FatMax brand hammer and told her he used it to kill the others, according to Sheriff's Detective Brad Maskell. He said authorities bought a similar hammer and matched tool markings on it to the wounds on the victims' skulls.

Duncan is not likely to cut a sympathetic figure for a jury. He has spent much of his adult life in prison for sexually assaulting a 14-year-old boy at gunpoint and was on the run when he was captured from charges he molested a 6-year-old boy in Minnesota.

The threatening writings on his personal blog only makes things worse.

"I have decided to give up on trying to convince people that I am a real person, with honest and good intentions, not some evil monster they should be afraid of," he wrote. "My intent is to harm society as much as I can, then die."

If Shasta testifies against Duncan, the details will be "extremely powerful," said Sweetser, the former prosecutor.

"If I was the defense attorney on this case, with everything I see, I would be looking to try and avoid the death penalty sentence," he said.

Christian Phelps, a criminal defense lawyer in Spokane, said Duncan's attorney will also have to walk a very fine line in trying to cross-examine Shasta and punch holes in her story without alienating the jury.

"The child is going to be awfully sympathetic to the jury," Phelps said. "It's a very, very tough position for a defense attorney."