LAS VEGAS — A judge refused to grant Margaret Rudin a mistrial Wednesday, saying prosecutors were on solid legal ground when they put her alleged lover on the witness stand and then attacked him as a liar and accomplice to murder.

Judge Joseph Bonaventure's ruling meant Yehuda Sharon, a holy oil salesman who prosecutors say was Rudin's paramour, spent another day before the jury, defending himself against charges that he and the so-called Black Widow killed her fifth husband, Ron, in 1994 to get at his $11 million fortune.

"Did you help kill Ron Rudin?" asked defense lawyer Michael Amador during an exceedingly friendly cross-examination. "Did you dispose of his body?"

"No, I did not," Sharon replied to both.

The Israeli man secured an immunity deal with prosecutors in 1995 in exchange for cooperation, but he provided them with little information, saying his only relationship with Rudin was as a financial advisor and denying any knowledge of her husband's murder.

Tuesday, in dramatic testimony the defense derided as a "little stunt tactic," prosecutor Gary Guymon accused Sharon of forging a gas station receipt to bolster his claim that he rented a van for a California business trip the week Rudin disappeared. Prosecutors contend that Sharon used the van to dump Rudin's corpse in the desert after Margaret Rudin shot him.

The defense was furious with the maneuver and asked for a mistrial as soon as court began Wednesday.

"They called Sharon not to elicit any evidence helpful to their case. They put him on the stand solely to impeach him," lawyer Tom Pitaro charged. Pointing to his client, he added, "All they did was say Yehuda Sharon was a bad guy. They never said he had anything to do with her."

But prosecutor Chris Owens countered that the Sharon's van and the alleged role it played in the murder were essential to the case against Rudin.

"Whether he made the trip to Nelson's Landing [the remote location where the body was found] or whether he made the trip to California — that's the heart of the case," Owens said.

Bonaventure agreed, but ruled that the prosecution could not call a California gas station manager to testify that the receipt was printed in 1996 and then doctored to look like a 1994 receipt.

But even denied such a witness, Guymon pressed on with the fraud charge. He put a copy of the receipt on a big-screen television before the jury, pointed to the digits in the date stamp, and suggested it was clear the year had been changed.

The gas station receipt (Court TV)

"Every one of those 4s but the one in '94' is clean and crisp," Guymon said. As one female juror leaned over the jury box to get a better view, Sharon shrugged and again denied manufacturing the receipt. When Guymon suggested he never volunteered the receipt to investigators in 1995 or 1996 because he hadn't yet forged it, Sharon replied that no one had ever asked him to see it.

The prosecutor also got him to admit that Rudin gave him papers pertaining to her husband's burial and assets to review just a few days after he had disappeared and a month before his charred remains were discovered. Other witnesses have testified that the 57-year-old socialite never seemed concerned when her husband went missing and was unemotional when told he had been murdered.

On cross-examination, Sharon tried to explain his poor relationship with the police; he is suing the Las Vegas Metro Police Department for defamation of character and other charges. He said that homicide detectives bullied him after he drove Rudin to the airport to attend her husband's funeral. Detective Jimmy Vaccaro, he said, intimidated him with phone calls and threatening voice mail messages.

"He put pressure on me that if she doesn't come back I was going to be arrested," Sharon said. He added that the information they gave to the media was wrong and cast him and Rudin in a bad light.

But Guymon ridiculed his complaints, asking him why he hadn't saved the threatening messages the way he clung to the 1995 receipt.

Sharon also elaborated on what prosecutors have admitted is an "airtight alibi" for the time when they believe Ron Rudin was shot. He said he was spending his third night with a Filipino woman he had met four days before and with whom, Amador euphemistically observed, Sharon was conducting "a somewhat intense relationship."

"I believe so," said Sharon, noting that he hoped the woman would help him sell chrism to churches in her homeland.

Also Wednesday, the jury watched the videotaped deposition of Ron Rudin's fourth wife, Karen Carmany-Gibbs, whose health problems prevented her from traveling to Las Vegas from her Arizona home. She testified that Rudin, whom she was married to from 1985 to 1987, had a distinctive habit of dealing with shaving nicks. He dabbed his face with a white, cloth handkerchief which he kept folded in quarters in a bathroom drawer, she said. That testimony is important because prosecutors used blood from a similar handkerchief as a sample of Rudin's DNA. Experts then matched that DNA to blood spots found in the couple's master bedroom, where Margaret Rudin allegedly shot her husband in the head.

Carmany-Gibbs also offered a glimpse into the victim's strange personality. She said he went to bed at 9 p.m. every night and was scared to leave the house after dark.

"He was afraid, afraid of what I don't know," she said.

She described him as an alcoholic who favored vodka and drank when his business did poorly.

When he began drinking, she said, he became verbally abusive and changed "from a nice gentleman who smiled into a man who didn't smile and had a mean, gruff voice and a mean-looking face."