(CBS News) It took years to find and convict the killer of Chandra Levy - a young, attractive Capitol Hill intern - but now that conviction could be thrown out.
Last month, federal prosecutors in the Chandra Levy case went before a judge and made a bombshell disclosure: Ingmar Guandique had been convicted of Levy's murder with the help of a witness whose credibility is now in doubt.
Citing safety concerns raised, the judge sealed court records and issued a gag order.
Susan Levy, Chandra Levy's mother, said, "The attorneys cannot even go in along with the people who are reporters or news people."
At a subsequent hearing in January, spectators were kicked out of the courtroom. The case is now so shrouded in secrecy, not even Levy's parents know what's going on. Robert Levy, Chandra's father, said, "Whether they have to have a new trial or have another suspect, or whatever, we don't know. They can't tell us because it's secret."
Sex, power, and murder are the recipe for a media firestorm, and in May 2001, when Levy, a beautiful young woman from California mysteriously vanished, suspicion fell on her congressman and paramour, Gary Condit.
One year later, her remains were found in Rock Creek Park. While Condit was never charged, his political career was derailed.
Guandique was convicted in 2010, on a case without any physical evidence linking him to the crime. But two women said he attacked them in Rock Creek Park around the time Levy disappeared, and a jailhouse snitch claimed Guandique confessed to the Levy murder.
His defense attorneys now accuse prosecutors of withholding the new information. Guandique has always maintained his innocence.
Robert Levy said, "He's a convicted rapist and an illegal alien. He's not legal at all or working or anything. He's just a criminal, so he shouldn't go free. But if he's innocent of murder then he shouldn't be in jail for it."
Susan Levy said, "No matter what goes on, our daughter is dead. It doesn't really matter except that they get the right person."
For "48 Hours" correspondent Erin Moriarty's full report, watch the video in the player above.