Part of Dylan Groene's skull shown to jurors

Part of Dylan Groene's skull shown to jurors »Play Video
BOISE -- A piece of Dylan Groene's skull with some hair was shown to jurors Wednesday during the sentencing trial of confessed child killer Joseph Duncan.

The skullcap fragment was found by investigators searching a remote Montana campsite after Duncan's capture and Shasta Groene's rescue in July 2005.

Duncan took the two children to the camp in the Lolo National Forest after he kidnapped them and killed their mother Brenda, older brother Slade, and Brenda's fiancee Mark McKenzie on May 16, 2005.

Duncan, who is representing himself, objected to admission of the evidence, but Judge Edward Lodge overruled him.

In Shasta's videotaped interview with police hours after she was rescued, the little girl said Duncan told her he shot her nine-year-old brother Dylan in the stomach accidentally, then shot him in the head to put him out of his misery.

John Webb, an FBI firearms expert from Virginia, testified he conducted many tests on the sawed-off Browning shotgun to determine if it could discharge by accident.

Webb said the only way he found that the gun could fire was by actually pulling the trigger.

Dr. Sharon Cooper, a forensic pediatrician, described in detail the agony of gunshot wounds to the stomach, but Dr. Cooper said from how Shasta described her brother's wounds, Dylan probably could have survived if he'd gotten proper medical attention.

Dr. Cooper said the description of the boy's injury - he was eviscerated, his sister said, with his "guts" hanging out - indicated it was "a very potentially salvageable injury."

"We see this on the battlefield fairly often," the doctor told the jury. "They can live for several hours like that."

Dr. Cooper also said Duncan may have had enough time to get Dylan Groene to a hospital from the remote western Montana campsite where the shooting occurred.

While in the Army, Dr. Cooper was assigned to child abuse cases on military installations in Hawaii and the Pacific Rim before becoming chief of pediatrics at Fort Bragg, N.C.

She said she performed a medical assessment of Shasta Groene after her rescue, interviewed her father, Steve Groene, and reviewed interviews of the girl by law enforcement officers.

Duncan, acting as his own attorney in the sentencing phase, suggested in cross-examining Dr. Cooper that the girl was exaggerating her brother's injury.

"How much in your experience do children tend to elaborate or exaggerate and fill in details ... especially after a traumatic experience like that?" Duncan asked.

Children who exaggerate are typically much younger, between 4 and 6, and lack the vocabulary to describe what happened to them, Dr. Cooper said.

Duncan asked whether the "guts" mentioned by the girl could have been RamDon noodles the boy had eaten earlier.

Dr. Cooper said that was unlikely because chewed-up noodles wouldn't look like intestines. Besides, she told the jury, food would spill out of an abdominal wound only if the stomach also had been pierced.

Shasta told police Duncan burned Dylan's remains.

Police officers and FBI agents described their detailed search of the Montana campsite after Duncan's capture.

In addition to the piece of skull, they found other small bone fragments and bits of clothing.

On the tape shown to jurors Tuesday, Groene, 8-years-old at the time, appeared composed while telling detectives about being raped by Duncan and forced to watch him torture, molest and kill her 9-year-old brother, Dylan.

Duncan, a convicted pedophile from Tacoma, Washington, faces the death penalty for his actions.

In December, he pleaded guilty to 10 federal charges related to
the 2005 kidnapping of the children and the slaying of Dylan.

Duncan has also pleaded guilty in state court to the slayings of
Shasta's older brother, mother and mother's fiance.

At one point during the interview, Shasta tells how
Duncan took Dylan to an old shack, made him stand on a bench,
wrapped wire around his neck then kicked the bench out from under
his legs until the boy nearly choked to death.

Duncan has a long string of arrests and convictions for crimes ranging from car theft to rape and molestation. He is suspected in the slayings of two half-sisters from Seattle in 1996 and is charged with killing a young boy in Riverside County, Calif., in 1997.

(The Associated Press contributed to this report.)