HAYWARD -- The family of Michaela Garecht is awaiting results of lab tests to tell them if a bone fragment found in a Linden well in San Joaquin County belongs to the Hayward girl who went missing 24 years ago.

Hayward police said Thursday morning that a 3-inch bone fragment unearthed with other remains in February was originally sent to an Arizona lab and has been forwarded to a Virginia lab for further analysis.

"We don't have any definitive answer as to whether this is a bone from Michaela," Hayward Police Sgt. Eric Krimm said. It will be several weeks before results are available, he added.

Michaela's mother, Sharon Murch, said Wednesday that she believed the remains are likely those of her daughter, who was 9 when she was kidnapped outside a Hayward corner store on Nov. 19, 1988.

Krimm said the age of the victim and the time period it was believed to be from were the only two clues linking the bone to Michaela's disappearance.

Hayward police received the fragment about two weeks ago. It was unearthed in February in a Linden well, which is believed to hold the victims of the so-called "Speed Freak Killers." The fragment belonged to a child between the ages of 5 and 13, police said, and Hayward officers hand-delivered it to a lab in Arizona "for testing in the possibility it may be that of Michaela."

It is now at a Virginia lab for more tests, Krimm said Thursday.

The bone fragment was originally delivered to Joan Shelley, the mother of 16-year-old murder victim JoAnn Hobson, after it was excavated from the Linden well earlier this year. The remains were originally identified as those of her daughter, and returned to her family for burial. But rather than bury the remains of her daughter, who vanished in 1985, Shelley sent the them to Dr. Eric Bartelink, director of the California State University, Chico Human Identification Laboratory.

In Bartelink's report, he states the use of large earth moving equipment led to "significant commingling" of the remains in the well, and that at least two other individuals were mixed in with the Hobson's remains.

In total, 28 human bone samples were selected for DNA testing, the report states.

Asked why she might send the bones for analysis even though she had been told they were her daughter's, Krimm said: "I think Ms. Shelley was looking for confirmation and closure."

The report opens up the possibility that other victims of the "Speed Freak Killers" may have been unidentified. Krimm said Thursday that Hayward police had custody of other bones that were believed to be from other victims.

"The other bones -- we have not even (attempted) to figure out who they belong to," Krimm said. The department was working with the FBI to figure out how to proceed with those remains, he said.

Herzog and Shermantine were convicted of four murders and suspected in the deaths of as many as 15 people in and around San Joaquin County from 1994 to 1998. They were arrested in 1999. The pair were nicknamed "The Speed Freak Killers" because of their methamphetamine addiction. Herzog's first-degree murder convictions were overturned by an appeals court and he was granted parole, but he committed suicide in January.

Staff writers Eric Kurhi, Katie Nelson and The Stockton Record contributed to this report. Reach Daniel M. Jimenez at 510-262-2728. Follow him at Twitter.com/DMJreports.