A bone fragment recovered from a back yard next door to the home of kidnapping suspects Philip and Nancy Garrido appears to be from a human, a sheriff's spokesman in Contra Costa County, Calif., said Tuesday.
Spokesman Jimmy Lee said an independent expert determined that the bone is "probably human," and investigators are sending it to the state of California's DNA lab for further testing.
"We will be requesting the state to see if it can develop a DNA profile on the fragment," Lee said in an e-mail Tuesday afternoon. "It should be noted that it is not uncommon to find Native American remains in Contra Costa County."
Lee did not return e-mails or phone calls late Tuesday. Authorities have declined to display the bone, describe it or specify where it was found in the yard. Philip Garrido, 58, and Nancy Garrido, 54, who are married, were arrested Aug. 26 and charged with 29 felony counts of rape and kidnapping in the 1991 abduction of 11-year-old Jaycee Lee Dugard, who authorities say bore Philip Garrido two daughters after she was snatched from a street near her home in South Lake Tahoe.
Authorities have been searching for evidence that might connect the Garridos to other kidnappings and homicides in the area, Lee said.
The bone fragment was recovered after several law-enforcement agencies, including the FBI, sheriff's office and local police, combed the back yard next door to the Garridos' home last week with dogs trained to detect human remains. Philip Garrido took care of the property when it was vacant in 2006, authorities said, and he sometimes lived in a shed in the back yard. During the search, investigators dug a trench at the back of the shed, but it was not clear whether the bone was recovered from that area.
The property's current tenant, Damon Robinson, allowed investigators to search, Lee said.
"The entire property is red-tagged and is off limits," Lee said Tuesday.
Investigators removed a van from the property Friday.
Dugard and her family remain in seclusion. Tuesday, a spokeswoman said the family would not comment on the investigation.