A judge on Thursday turned aside a defense effort to derail Scott Peterson's (search) murder trial, rejecting defense motions for a mistrial or outright dismissal of charges on the grounds that an investigator allegedly lied on the witness stand.

Defense attorney Mark Geragos (search) maintains Modesto Detective Allen Brocchini (search) fabricated part of his testimony to help prosecutors prove that Peterson killed his pregnant wife, Laci, in their home and dumped her body into San Francisco Bay.

It was the third time the aggressive defense lawyer has asked for a mistrial, but the first he had asked for the case to be dismissed. Judge Alfred A. Delucchi (search) also quickly denied the earlier requests.

Geragos has asserted that Brocchini lied on the stand about a tip that police received several days after the remains of Laci Peterson (search) and the couple's fetus washed onto a San Francisco Bay shore.

Prosecutors allege Peterson dumped his wife's pregnant body in the bay after killing her at their Modesto home. Geragos says someone framed Peterson after learning his alibi — that he took a solo fishing trip on the bay the day his wife vanished.

Last month, Brocchini told jurors he spoke to a tipster who alleged that, in 1995, Scott Peterson said he would dispose of a body by sinking it in the ocean after using duct tape to "tie a bag around the neck."

That appeared damaging because police found duct tape on Laci Peterson's tattered clothing and badly decomposed remains. But Geragos said Thursday that the tipster never mentioned duct tape.

"The only reason this detective would have injected ... duct tape," Geragos said, "was to stir the pot, so to speak."

Prosecutor Rick Distaso described Brocchini's testimony as not "gross negligence" but an unintentional mistake. To declare a mistrial or dismiss the charges, Delucchi would have had to judge intention on Brocchini's part.

Geragos argued that this was just one instance in a history Brocchini had of contempt for legal boundaries while on the witness stand. A Stanislaus County judge ruled Brocchini's comments during a 1998 home invasion robbery case declared a mistrial after determining his testimony might have prejudiced the jury, according to court documents.

Geragos implied Thursday that Brocchini thought prosecutors were losing the Peterson case, so he decided to create ground for a mistrial — and a chance for prosecutors to start over.

"He knows that in another case when he does a similar stunt the court grants a mistrial ... and when they started all over again they got a conviction," Geragos appealed to Delucchi.

In the robbery case, the judge warned Brocchini not to mention any other crimes the defendants may have perpetrated. Nonetheless, under questioning, Brocchini told jurors that while investigating the home invasion case, he had been interested in talking with one defendant about his potential involvement in another robbery.

Delucchi began Thursday by deciding another issue, ruling that ABC could not be ordered to turn over unaired copy of Peterson's interview with Diane Sawyer.

During that and other interviews, Peterson lies about what he told police regarding his affair with a massage therapist, his alleged motive for murder.

Delucchi also quashed a subpoena prosecutors issued that would have required a Modesto Bee photographer and librarian to verify that a picture of Peterson smiling at a vigil for his wife was published in the newspaper.