Police are trying to gain access to taped conversations recorded in 1969 between one of Charles Manson's followers, Charles "Tex" Watson, and an attorney who died three years ago.
Manson and Watson are serving life sentences for the Tate-LaBianca murders in 1969. The 12 unsolved murders reportedly occurred near the Spahn Ranch, the Manson family's hangout during its Southland killing spree more than 40 years ago.
"The key is 'they may be tied to.' They occurred in the same basic type of circumstances, the same basic time frame that the Manson family was active, and in the same region, so we're thinking there's a possibility," said LAPD Cmdr. Andrew Smith.
The recordings are now in the hands of a trustee in a bankruptcy proceeding involving the late attorney's law firm.
In May, a bankruptcy court judge ruled that the LAPD should get the tapes because Watson waived his right to attorney-client privilege when he made them available to the co-author of his 1978 book "Will You Die for Me? The Man Who Killed for Charles Manson Tells His Own Story."
Watson is fighting police access to the tapes, and a federal judge has temporarily blocked police from executing a search warrant at an office where the tapes are kept.
U.S. District Judge Richard A. Schell criticized the LAPD for what he called an apparent attempt to circumvent a court order making the tapes off limits until Watson's appeal of a previous ruling in bankruptcy court can be heard.
Watson, now 66, has argued in court documents that he waived his attorney-client privilege only for the book. He has stated that he's willing to allow the LAPD to listen to the tapes, but not take possession of them because he's concerned that the media would gain access as well.
"It'd be a bit of a stretch, but until we get those tapes and listen to them, we're never going to know," Smith said. "We really feel like we owe it to the victims in this case, and we owe it to their family members to do everything we can to investigate it fully and give them some closure if we can."
The Associated Press contributed to this report.