Authorities to dig up Manson family ranch

(CNN) -- Authorities said Friday they will begin digging for evidence of graves at a California ranch that once was home to the infamous "family" of convicted killer Charles Manson.

Soil testing to determine the possible presence of buried bodies was inconclusive, authorities said Friday, so "exploratory excavation" will be done later this month, Inyo County Sheriff Bill Lutze said.

The dig will be carried out "to either confirm or put to rest speculation that bodies may remain there from the Charles Manson era," Lutze said in a written statement.

In March, search crews found indications that human remains may lie within a few yards of Barker Ranch, the onetime hideout of the "Manson family."

The sites were first identified by trained dogs, and testing equipment from the Oak Ridge National Laboratory also indicated the possible presence of remains, said Sgt. Paul Dostie of the Mammoth Lakes, California, police department.

The excavation will take place at sites where cadaver dogs gave mixed indications and soil testing was inconclusive, Lutze said.

"There was no consistent response from the dogs that searched, and no conclusive findings from the soil samplings tested by top experts in the field," he said. "Therefore, I believe the only way to determine once and for all whether there are bodies buried at Barker Ranch from the time of the Manson family is to proceed with limited excavation in a very few areas."

The excavations will begin May 20 and will continue through about May 23, although additional days will be added if needed, he said.