A sheriff's spokesman says a bone fragment found next to the home where Jaycee Dugard was held captive for 18 years by Phillip Garrido is probably human.
Contra Costa County Sheriff's Department spokesman Jimmy Lee cautioned that is not unusual to recover Native American remains in the area.
But the Contra Costa County Sheriff's Department has asked the state crime lab to perform DNA tests on the fragment, which was found on Aug. 31.
Garrido took care of the neighboring house while it was vacant and sometimes camped in the yard in 2006.
He and his Nancy Garrido face 29 felony counts for what he allegedly did to Dugard. Both husband and wife have pleaded not guilty.
"We are taking very seriously the possibility that he could be connected to some others," San Francisco FBI Special Agent Joseph Schadler told ABCNews.com.
Rod Garecht told ABC News that police have contacted him looking for any connection between Jaycee's 1991 abduction when she was 11 and the 1988 kidnapping of his 9-year-old daughter Michaela.
"Anything to keep her in the news and keep people talking about her is good," Garecht said today.
Like Jaycee Dugard, Michaela Garecht was grabbed off the street in broad daylight, pulled into a stranger's car in front of witnesses. His daughter, with her dirty-blonde hair and wide smile, could be Jaycee's twin.
Michaela would now be 30, a year older than Jaycee who was found alive last week at age 29 along with the two daughters fathered by Phillip Garrido.
When Garecht saw the story about Jaycee, Garecht said he wondered if the woman police had found was actually Michaela.
"When I saw her, the picture they showed of her as a child looked a lot like my daughter," he said. "I kept thinking it was Michaela and not that other girl."
Though police have confirmed Jaycee's identity, "there's always a glimmer of hope," Garecht said. "There's still a possibility that she's alive," Garecht said, although he added, "not much possibility."
Michaela Garecht and Jaycee Dugard were two in a string of young girls who disappeared in the late 1980s and 1990s. Schadler said that they are looking specifically at abductions that took place after Garrido was paroled in the late 1980s after serving prison time for kidnapping and rape.
It's been more than 20 years since 13-year-old Ilene Misheloff was kidnapped while walking home from school in Dublin, Calif. She was last seen on Jan. 30, 1989, less than 200 yards from a shortcut over a creek bed that her parents learned Ilene used only after her disappearance.
Misheloff said that while the news that Jaycee Dugard had been found 18 years after her 1991 kidnapping lifted his hopes, he did not immediately believe there was a connection between her case and his daughter's abduction.
Though younger than the others missing girls, a 4-year-old girl also disappeared from northern California in 1991, just months after Jaycee was snatched. Amanda Campbell, also known as Nikki, was last seen two days after Christmas when she left her brother to bike to a nearby friend's house.
"The issue with Jaycee being found is just something that reinforces our hope," Mike Misheloff told ABCNews.com.