Los Angeles police said this week that up to a dozen more unsolved murders might be linked to the notorious Manson family, and according to The LA Times, they think they know where to find evidence to back up their theory.

Their request for that evidence, however, was denied by a federal judge in Dallas on Thursday, according to The Associated Press. The judge said would just have to wait until an appeal of a bankruptcy court's hearing can be heard.

Prosecutors said that tapes that feature Manson acolyte Charles "Tex" Watson speaking to his attorney could hold clues to numerous other unsolved murder cases now more than 42 years old. Attorney Bill Boyd died in 2009, and his former law firm has since become embroiled in a bankruptcy proceeding. Watson appealed an earlier ruling ordering the law firm's bankruptcy trustee to turn the tapes over to police, and he's since declared that the Manson family was not involved in any additional murders.

Watson is serving a life sentence in connection to seven counts of murder orchestrated on Charles Manson's orders, including the 1969 killing of actress Sharon Tate, who was 8 1/2 months pregnant. The string nine total killings by Manson's followers shocked the nation for their brutality, and none of the Manson family members have been granted parole.

Cmdr. Andy Smith of the Los Angeles Police Department said the 12 additional killings being investigated are "similar" to the Manson family's killings. "Our detectives need to listen to these tapes," he told NBC 4 in Los Angeles. "The tapes might help with solving these murders."

This video is from NBC 4 in Los Angeles, broadcast Friday, October 19, 2012.

View more videos at: http://nbcchicago.com.