Updated

The case against the man accused of killing federal intern Chandra Levy is flawed because it is largely based on the accounts of "jailhouse snitches" interviewed years after the slaying, defense attorneys said Thursday.

As Ingmar Guandique made his initial appearance in District of Columbia Superior Court, public defenders Santha Sonenberg and Maria Hawilo argued that a March 3 affidavit did not show probable cause for his arrest. Guandique wore a baggy orange jumpsuit and handcuffs. He said little, speaking softly and through an interpreter when asked to state his name.

Guandique, who is accused of sexually assaulting and killing Levy in 2001 in a Washington park, was charged with first-degree murder Wednesday.

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Click here for the arrest warrant and affidavit (FindLaw).

Eight of the dozen prosecution witnesses outlined in the affidavit were known to prosecutors for years, Sonenberg said, yet no arrest was made until after others were interviewed beginning in 2008. Of those, three were "jailhouse snitches," she said.

"There is not a single witness to ever see Mr. Guandique and the decedent together and little information unknown to the government in 2002 beyond the made-up claims of unbelievable self-serving jailhouse informants," the attorneys said in a statement after the hearing.

The judge, however, found that police had probable cause to arrest Guandique and scheduled another hearing for May 27. Guandique, who is also serving a 10-year sentence in California for a separate assault, was to remain held at the D.C. jail until then.

A representative for the Levys said the family would not comment on Thursday's hearing.

The 24-year-old Levy had just completed an internship with the U.S. Bureau of Prisons when she disappeared in May 2001 after leaving her apartment in jogging clothes. Her remains were found in Rock Creek Park a year later.

The case has been blamed for destroying the political career of former U.S. Rep. Gary Condit of California, who was romantically linked to Levy. Authorities questioned the Democrat who represented the Modesto district where Levy grew up, but he was never a suspect.

The arrest warrant and affidavit released last month make no mention of DNA or other forensic evidence pointing to Guandique. But U.S. Attorney Jeffrey Taylor has said that the "cumulative weight" of circumstantial evidence would be enough for a conviction.

None of the witnesses in the affidavit is named; two directly link Guandique to Levy's death.

The affidavit says one of those witnesses was present when Guandique allegedly heard a recent news report about authorities' plan to arrest him in the Levy murder. The witness claims Guandique said he was involved in her slaying and described the incident in detail. Given that Guandique was in jail at the time, it's likely that witness is an inmate.

Another witness also said that Guandique admitted to killing Levy, though police say the account Guandique provided that person was "inconsistent in some respects with accounts he gave to other witnesses." The affidavit does not specify the discrepancies.