A forensic biologist testified that she found blood and charred flesh on tools located in Chad Daybell's property where his new wife Lori Vallow Daybell's children had been buried.

Katherine Dace, who works for Idaho's state crime lab, testified Thursday that she performed blood testing on 18 different hand tools taken from Chad Daybell's property in Salem, Idaho, including shovels.

"I found several presumptive positive blood stains on the tools, and on several of the tools I found what could be charred flesh," she said, adding that she photographed the tools and took samples of the flesh for DNA testing.

While DNA profiles were not found on many of the tools, she described a sample of "soft texture" taken from the back of one shovel and testified that DNA tests indicated it was 16-year-old Tylee Ryan's remains. She said a partial DNA profile was located on a pick ax that also matched the girl's DNA profile.

Tara Martinez, a forensic scientist who works for the Idaho State Police, also testified a black plastic bag used to wrap 7-year-old JJ Vallow's body had prints that matched the right palm and right little finger of Alex Cox — Lori Daybell's brother who died in December of 2019.

Lori Daybell is on trial for murder, conspiracy and grand theft in the deaths of her two children, Tylee and JJ. She is also charged with conspiracy in connection with the death of Tammy Daybell, her husband's former wife. Chad Daybell is charged with the same three deaths and will face a separate trial.

It has been an intense week of testimony as jurors have heard graphic details about the burial site for the two children and details about their autopsies that had not previously been released publicly.

Dr. Angi Christensen, a forensic anthropologist for the FBI, finished testifying Thursday about her analysis of bones she was asked to evaluate. She said her study took roughly a month.

Lori Daybell's head was down at the defense table and she didn't look up at images of bones projected on a screen in the Boise courtroom as Christensen testified about sharp trauma injuries to the hipbone and sacrum of Tylee Ryan.

JJ died from asphyxiation with a plastic bag over his head, according to Dr. Garth Warren, a forensic pathologist. He said there were signs of a struggle, with scratches on JJ's neck, and he was bound with duct tape on his hands and wrists.

Warren said the cause of death for Tylee was homicide by unspecified means. Examiners could not determine her exact cause of death since her body was dismembered and burnt.

Douglas Halepaska, a forensic examiner in the FBI's firearms and toolmarks unit, testified Thursday about specific marks on Tylee's bones, saying some appeared to have been made through stabbing actions with a sharp point as well as through chopping actions from a blade.

He said he couldn't identify specific tools, but believes some injuries could have resulted from bladed tools such as a hatchet, cleaver or machete. Other injuries were consistent with injuries from a serrated blade and others from a knife or cleaver with a point. Halepaska described other injuries as "compression actions" as a result of some kind of force.

David Sincerbeaux, a forensic analyst in the Idaho State Lab, analyzed burnt flesh as part of the investigation. He said gasoline was present in the samples he analyzed.

FBI special agent Steve Daniels testified Wednesday about the burial site. JJ's body was found under rocks and boards, placed so wild animals could not disturb the site. Tylee's remains were in a melted green bucket, her skull was found underneath the bucket.

Daniels said both children were buried about 2 feet under the ground, near the pet cemetery in Chad Daybell's backyard.