LOS ANGELES - The LAPD on Thursday announced it has open investigations on a dozen unsolved homicides near known Manson Family hangouts around Los Angeles.

The revelation came amid a legal battle to obtain hours of audio tape recordings between former Charles Manson follower and convicted murderer Charles "Tex" Watson and his lawyer.

"We have an obligation to the families of these victims," Cmdr. Andy Smith told NBC4. "Our detectives need to listen to these tapes. The tapes might help with solving these murders."

News of the open investigation was first reported by the Los Angeles Times Thursday and confirmed to NBC4 by LAPD officials. Smith told the Times the 12 murders they are investigating "are similar to some of the Manson killings."

Also on NBC Los Angeles: New direction in Grim Sleeper investigation

Manson and his followers shot to infamy in 1969 after the murders of pregnant actress Sharon Tate and four others at a Benedict Canyon home in the hills above Los Angeles. That rampage was followed the next night by the murders of Leno and Rosemary LaBianca in their Los Feliz home.

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 The unheard recordings sought by the LAPD were made more than four decades ago, after Watson’s arrest for his role in the Tate-LaBianca slayings.

Charles Manson scheduled for 12th parole hearing, new photo released

LAPD’s effort to obtain the tapes was not known publicly until it was reported by NBC4 News in May. And Watson has been fighting to keep those tapes under wraps. Police believe they may hold clues to "additional unsolved murders committed by followers of Charles Manson."

Earlier this year, a court order authorized LAPD to take possession of the recordings, but Watson’s lawyer obtained a "stay" order effectively stopping the release of the tapes while his appeal is heard.

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 The LAPD tried to obtain the tapes using a search warrant, according to the Times. But on Oct. 9, a federal judge in Texas granted an emergency order barring police from executing a search warrant at an office where the tapes are kept.

For now, the tapes remain in the custody of a Texas bankruptcy trustee, who took responsibility for them after the 2009 death of Watson's original attorney, Bill Boyd. Boyd had made the recordings.

Watson, now 66, is serving a life sentence in California's Mule Creek State Prison in Ione, Amador County, outside Sacramento.

LOS ANGELES -- Former Manson follower and convicted murderer Charles "Tex" Watson has filed a legal motion to stop Los Angeles Police from taking possession of long unheard audio tape recordings of Watson speaking to his attorney.

The recordings were made 43 years ago, after Watson's arrest for his involvement in the Tate-LaBianca murders of seven people, including pregnant actress Sharon Tate.

Only in recent months did police learn the tapes had surfaced in a Texas bankruptcy proceeding, following the death of Watson's attorney Bill Boyd.

See the original report at NBCLosAngeles.com

LAPD’s effort to obtain the tapes was not known publicly until it was reported by NBC4 News last month.

Police want the tapes in the belief "Watson discussed additional unsolved murders committed by followers of Charles Manson," according to a letter the department sent the East Texas Bankruptcy Court.

Watson, now 66, is serving a life sentence in California's Mule Creek State Prison in Ione, Amador County, outside Sacramento.

Last month, bankruptcy Judge Brenda T. Rhoades signed an order that the tapes be turned over to LAPD effective Thursday, June 14.

Last week, a legal motion signed by Watson himself asks the court to "revise" its decision.

Watson proposes that LAPD be allowed only to listen to the tape recordings, and not be given possession of them. The listening would be done "in the presence of the trustee or a court designed person," according to Watson's filing.

Such an arrangement is not adequate, according to LAPD Commander Andrew Smith.

"Just to sit down and listen with a lawyer in the room, that's not really how our detectives get into the details," Smith told NBC4 News.

In Watson's filing, he wrote of a concern that if LAPD gets the tapes, media could use the Freedom of Information Act to obtain them, and that "could be hurtful to the families of victims."

Police note that in the 1970s, Watson allowed the tapes to be released to a prison chaplain, Ray Hoekstra, for the purpose of writing a book on Watson published under the title, "Will You Die for Me?"

The book was written "to respect the victim's (sic) families...to show delicate consideration when sharing the graphic details of the crime," Watson wrote. The book did not reveal additional unsolved murders.

Watson contends he did not discuss such murders on the tapes.

"That remains to be seen," Smith said. "We've got eight hours of audio tapes to listen to. Hopefully we can solve some crimes with it."

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Eight hours of audio never before heard by law enforcement has been requested by the Los Angeles Police Department, and it could link followers of the Manson Family to unsolved murders.

In a letter dated March 19, LAPD Chief Charlie Beck requested "eight hours or so" of audio recordings between attorney Bill Boyd and his then-client Charles "Tex" Watson, according to a U.S. bankruptcy filing.

Watson, the former right-hand man of Charles Manson, is currently serving a life sentence for his involvement in the 1969 Manson Family murders.

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Although the LAPD has yet to receive the recordings, police believe the interviews could contain information about unsolved murders.

"The LAPD has information that Mr. Watson discussed additional unsolved murders committed by followers of Charles Manson," Beck wrote in a request to a trustee with the U.S. Department of Justice.

The LAPD's request corresponds to the liquidation of Boyd's Texas-based law firm as part of a bankruptcy proceeding. Boyd, who died in 2009, represented Watson beginning in 1969 and "for some time thereafter," according to Beck.

"It is requested that the original recordings be given to the LAPD in order to determine if information regarding unsolved murders was included in the recordings. The LAPD, Robbery-Homicide Division will be investigating Mr. Watson's recordings…" wrote Beck.

Document: LAPD Chief's Letter Requesting Audio Recording (PDF)

A bankruptcy court hearing is scheduled for Tuesday in Plano, Texas, to determine if the audio will be given to police.

The recordings remained private until September 1976 when Watson authorized its sale to author Chaplain Ray Hoekstra to help cover unpaid legal fees. Hoekstra used the material for his 1978 book "Will You Die For Me?"

Watson was sentenced to death for the murders of Abigail Ann Folger, Wojciech Frykowski, Thomas Jay Sebring, Steven Earl Parent, and Sharon Tate Polanski. California temporarily suspended the death penalty in 1972, and Watson has been serving a life sentence ever since. He was most recently denied parole last November.

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