Prosecutors withheld evidence that might have led to child pornography possession charges against former JonBenet Ramsey slaying suspect John Mark Karr to be thrown out, defense lawyers told a judge Tuesday.

Karr's attorneys said prosecutors deliberately withheld a September interview with his ex-wife, Lara Knutson, in which she told them the computer from where they found the five allegedly illegal images did not work at the time of his arrest.

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Karr's attorneys are seeking to have the charges against him dismissed. Arguments in the case were delayed Tuesday while his lawyers asked a judge to order prosecutors to turn over more evidence. They are expected to resume Wednesday.

Karr, 41, is accused of having five images of child porn on his computer when he was arrested in 2001. If convicted of the misdemeanor offenses, it is unlikely Karr would face jail time, as he already served time when first arrested five years ago, prosecutors have said.

Knutson's lawyer, Michael Rains, who has read a transcript of his client's interview, said it's not as clear-cut as defense lawyers claim. He said the couple was estranged at the time and sleeping in different rooms, and not intimately aware of each other's lives.

"The way I read this transcript is she's simply not certain," he said. "She's clearly wrestling with memory issues."

Chief Deputy District Attorney Joan Risse said that the computer from Karr's house must have been working, since a Sonoma County detective was able to find the five illicit images on its hard drive.

Karr's defense team also is seeking to invalidate the search warrant that led to the seizure of the computer, claiming a detective failed to disclose that his confidential informant suffered from bipolar disorder, depression and post-traumatic stress disorder.

The computer has been a recurring issue in the case. Investigators conceded they lost Karr's computer some time in the past five years, but claim to have found copies of the data recently.

Karr, a former teacher, fled before his trial in 2001. He was arrested in Thailand last month after suggesting he killed JonBenet, a 6-year-old beauty queen, in her Boulder, Colo., home in 1996. But Colorado officials dropped him as a suspect after DNA failed to connect him to the crime, and he was extradited to California last month to face the five-year-old child porn possession charges.