LOS ANGELES (AP) _ In a flurry of motions filed Tuesday, O.J. Simpson's lawyers sought appointment of a special prosecutor to investigate possible police perjury in Simpson's murder trial as well as limits on prosecution plans to portray a star defense witness as a drug-using womanizer.

Most of the day's developments happened outside the jury's presence, including testimony from Simpson's friend, Gretchen Stockdale, who confirmed Simpson left her a phone message a few hours before the murders of his ex-wife and her friend.

Prosecutors want the tape recording of the message in which Simpson reportedly says, ``Hey, Gretchen, sweetheart, it's Orenthal James, who is finally at a place in his life where he is like, totally, totally, unattached with everybody. Ha haaaah!''

Stockdale, a former Los Angeles Raiders cheerleader and lingerie model, said she met Simpson in 1988 and they became friends. She said they ran into each other at social events and she consulted him about a business investment.

Prosecutor Marcia Clark seized the opportunity to try quizzing Stockdale whether her relationship with Simpson was intimate, but the judge cut off such questioning.

Stockdale said she turned over the voicemail tape of Simpson's message to a defense investigator last year and kept an extra copy on her own tape recorder. But she said she later taped over that copy because ``it was no longer of any importance to me.''

Superior Court Judge Lance Ito ordered Clark to have her investigators contact Stockdale's answering service to determine whether they kept a copy of the message.

Sequestered jurors were sent back to their hotel after only two hours of testimony while Ito considered a plethora of legal issues before him and another judge briefly took over Ito's bench. Testimony wasn't expected to resume until Wednesday afternoon at the earliest.

The defense asked Ito to limit cross-examination of Kary Mullis, a Nobel Prize-winning chemist, on his relationships with women, political beliefs and well-known use of LSD. Mullis also has been prosecuted for domestic abuse.

``Since the time of Plato, scholars have recognized that one cannot judge the merits of an argument based on the character and lifestyle of the person advancing the argument,'' the defense motion said. ``Scientific arguments ... are no exception to this principle.''

Simpson's lawyers have been waffling on whether to call Mullis, and by Tuesday afternoon the motion hadn't been argued in court and it was unclear whether he would ever take the stand. Combative prosecutor Rockne Harmon has vowed to expose Mullis' unconventional lifestyle to jurors if he testifies.

Mullis has been in court listening to other scientific witnesses for several days. On Tuesday, he heard Terence Speed, a statistician from the University of California, Berkeley, tell jurors that error rates are important in calculating the odds whether Simpson's blood is linked to the murders.

Mullis won the Nobel Prize for discovering PCR, or polymerase chain reaction, which is a way to endlessly reproduce minute fragments of DNA. The process allows testing of DNA samples whose poor quality or small quantities formerly rendered them useless.

Mullis' process, however, is highly sensitive and easily subverted by contamination, experts have said. The defense argues that contamination of evidence in the Simpson case has made PCR results meaningless.

In another development, Ito left the bench briefly and turned his courtroom over to another judge for arguments on a Los Angeles Police Department internal affairs investigation into news leaks. Ito said he wanted to avoid any appearance of a conflict because his wife, a police captain, now works for the Internal Affairs Division.

Superior Court Judge John Reid listened to arguments on a defense request for files on the investigation, but he postponed a ruling until Wednesday, when Ito is to decide if the matter is material to the trial.

Ito said he would also decide whether to order two reporters to testify about news leaks. If he issues such an order, he said he expects an appeal to be filed citing the Shield Law, which protects reporters and their sources.

The motion for a special prosecutor, meanwhile, was aimed at Detective Mark Fuhrman and the LAPD, targets of defense attacks throughout the trial. Analysts said it might be nothing more than a defense ploy to unnerve their opponents.

``One has to wonder whether the defense really wants this or is just using it to put the prosecution and police on a little more of a defensive mode and distract them from the issues of the case,'' Loyola Law School professor Stanley Goldman said.

The defense contends a special prosecutor is needed because of the prosecution's ``evident disinterest'' in investigating perjury by its own witnesses and the judge's ``failure to remedy the evil addressed herein.''

The motion suggested that Ito erred in limiting defense access to Fuhrman's police and Marine Corps personnel records as well as Fuhrman's words to a psychiatrist more than 10 years ago about alleged feelings of deep racial hatred.

Simpson's lawyers have labored to show the detective was consumed by racial bigotry and motivated to frame the black football star. Fuhrman has denied the allegations.

This week, the assault on Fuhrman picked up steam when the defense won access to a North Carolina professor's tapes on which the detective uttered the word ``nigger'' 27 times. Fuhrman testified at Simpson's trial that he hadn't used that word with regard to blacks in the past decade. The interviews with Fuhrman were recorded from 1985 to 1994.

Matthew Schwartz, Los Angeles attorney for professor Laura Hart McKinny, said she wouldn't appeal the decision ordering her to turn over her tapes and to testify.

``Objectively speaking, I'd have to say that they could be crucial to the defense,'' Schwartz said of the tapes, which he predicted would have an emotional impact on the jury, which includes nine blacks.

If jurors find Fuhrman lied on the stand, they will be entitled to throw out all of his testimony. But admissibility of the tapes at trial has not been decided, and the defense motions showed a wide-ranging effort to undermine Fuhrman on several different fronts.

The bloody glove that Fuhrman said he found behind Simpson's house was the subject of still another defense motion. Simpson's attorneys said prosecutors should be barred from showing jurors videotapes of Simpson wearing gloves when he was a commentator on football game broadcasts.

Prosecutors maintain the gloves in the pictures could be the ones worn during the June 12, 1994, murders of Nicole Brown Simpson and Ronald Goldman.

The defense said the prosecution ``failed to establish any link'' between the gloves Simpson wore on the broadcasts and the gloves in evidence. One glove was found near the bodies, its mate at Simpson's estate.