(CNN) -- A dig for buried bodies at the ranch where murderous cult leader Charles Manson and his followers once lived ended Wednesday with no human remains found, authorities said.
Inyo County, California, Sheriff Bill Lutze authorized the dig, which began Tuesday, at Barker Ranch "to confirm or put to rest speculation that bodies may remain from the Charles Manson era," a statement said.
Manson and four others were convicted of murder and other charges in connection with a two-night spree in 1969 that left actress Sharon Tate and six others dead.
Manson is serving a life sentence in a California prison.
In March, search crews found indications that human remains could be buried within a few yards of the ranch in Death Valley in east-central California.
The sites were first identified by cadaver dogs, and testing equipment had shown the possible presence of remains, police said.
Investigators used radar, magnetometers, lasers and other tools and techniques during the search, which included five "hot spots" where remains were thought to be. Watch how an enduring mystery led to the dig »
The largest site of the five yielded a bullet casing. Animal bones and what appeared to be ashes were found at others.
Barker Ranch is National Park Service property and was closed during the excavation.
CNN had sent letters to Manson and cult member and co-defendant Tex Watson asking if there were victims buried behind the ranch.
Manson did not respond, but Watson did, saying in a letter that no one was killed while he was at the ranch but that he didn't know what may have happened after he left.