Bone fragments found near a crumbling chimney are from a 2- to 4-year-old child but do not conclusively identify a missing 3-year-old boy whose foster parents are charged in his murder, the Hamilton County coroner said Thursday.

Dr. O'dell Owens said the 18 fragments, the largest not even an inch long, were found near an old chimney in rural Brown County. Forensic scientists determined their age from growth plates in the bones, he said.

Owens called the evidence "pretty solid" that the fragments were from the body of Marcus Fiesel, who was reported missing in August. But DNA samples cannot be retrieved from the bones.

"When you're dealing with burnt bodies, you lose a lot of evidence," Owens said. "The DNA that is being processed came from a small piece of tissue that was found."

Owens declined to describe the tissue or to elaborate on other possible clues, a button and piece of fabric found at the chimney. He said to do so might jeopardize the investigation of the boy's death.

Foster parents Liz and David Carroll Jr. left Fiesel in a closet, bound in a blanket, when they left their Clermont County home for a family reunion in Kentucky last month, prosecutors contend.

The boy was dead when the Carrolls returned two days later, and David Carroll made repeated trips to neighboring Brown County to try to burn the boy's body, the prosecutors say.

Owens said traces of gasoline were found among the bags of soil taken to his lab from the chimney area. He believes the boy's body was not completely burned, and that some remains were dumped in the Ohio River, which runs along Brown County's southern border.

"It takes a tremendous source of heat to really burn a body totally up," Owens said.

Also Thursday, the Carrolls entered written not guilty pleas in Clermont County Common Pleas Court to numerous charges, including murder. Judge Jerry McBride set bond at $10.1 million each, the same amount set in Hamilton County, where they were first charged with involuntary manslaughter and several lesser crimes.

Public Defender Dan Hannon represented the Carrolls at the arraignment, but said his office would request that other attorneys be appointed because of a conflict of interest, which he declined to describe.

Although the Carrolls reported the child missing in Hamilton County, and authorities there led the investigation into his disappearance, prosecutors in the two counties agreed to try the most serious charges in Clermont County, where they believe the boy died.

Hamilton County authorities still intend to prosecute the couple on charges of inducing panic and false alarms. Liz Carroll also was charged with two counts of perjury in Hamilton County.

A Clermont County grand jury on Wednesday indicted the Carrolls on the new charges, which include murder, kidnapping, involuntary manslaughter, felonious assault and three counts of endangering children. David Carroll also is charged with gross abuse of a corpse.

The Carrolls will be tried separately. A pretrial hearing for Liz Carroll, 30, was set for Wednesday, and a hearing for David Carroll, 29, was set for Sept. 22.

The murder count carries a sentence of 15 years to life. With convictions on other charges, the Carrolls each could face sentences of about 35 years to life, Assistant Clermont County Prosecutor Woody Breyer said.

Nine days after authorities believe the Carrolls returned home to find the boy dead, the couple reported on Aug. 15 that the boy had gone missing from a public park. For four days, hundreds of searchers helped authorities look for the boy.

The Carrolls were arrested in Hamilton County on Aug. 28, based on information supplied by a woman who lived with the Carrolls, prosecutors said.

"This is a circumstantial case in many areas," Owens said, but he believes the evidence found by the old chimney backs up the woman's story.

"You have an eyewitness who said this is what happened here," he said.

Prosecutors have said the woman who supplied the information will not be charged with a crime unless she has lied and had some role in harming the child.

(Copyright 2006 by The Associated Press. All Rights Reserved.)