Northern California investigators probing two old kidnapping cases say some of the bone fragments found on the property of a man charged in a separate abduction are likely from animals.

Hayward police Lt. Chris Orrey said Thursday that preliminary test results from some fragments collected on Phillip Garrido's property show they are likely not human. Orrey says more bone fragments found there still await testing.

PHOTOS: Missing Girl Found 18 Years Later

Hayward police searched the Garrido property last month for any links to the kidnapping of Michaela Garecht in 1988. Dublin authorities also combed for evidence related to the 1989 disappearance of Ilene Misheloff.

Garrido has been charged for allegedly kidnapping Jaycee Dugard in 1991 and holding her captive in his Antioch backyard for 18 years. He and his wife, Nancy, have pleaded not guilty.