Knox's lawyers say the 23-year-old Seattle student is already nervous about her appeal next month against her 26-year sentence for murder.
CBS News correspondent Allen Pizzey reports that Knox arrived in a closed penitentiary police van Friday for the preliminary hearing.
If the charge of slandering eight police officers is thrown out, it will draw into question the conviction for murder, but if the judge rules against her and allows the slander case to proceed, Knox faces more time in prison. If the case goes ahead, the prosecution is likely to demand she be given a life sentence.
Witnesses in the courtroom Friday said Knox, who cut her hair during the hot summer in jail, appeared "drawn and pale," and that she had gained weight.
The slander charge is based on statements she made while being interrogated as a possible witness after the discovery of her housemate, British student Meredith Kercher, in a blood-spattered room.
"I was very, very scared because they were treating me so badly and I didn't understand why," Knox previously told the court. She said she only confessed to being in the house at the time of the murder after she was hit by police.
The scene in court today was almost déjà vu. The judge is the same one who originally committed her to trial…the prosecutor was on the state's team, and the lawyer representing the police is also representing Kercher's family in a civil suit against Knox.
Outside the courthouse, the media circus continues to grow.
Two movies, one of them starring "Heroes" actress Hayden Pennettiere as Amanda Knox, are in the works, and two books have already been published.
A former jail-mate wrote that Knox was originally not treated well by the other prisoners, but was accepted once she had been convicted of the murder. Two more books are due out soon, and the slander hearing reconvenes in a week's time.
Knox's parents, Curt Knox and Edda Mellas, spoke with "Early Show" co-anchor Harry Smith Friday. Curt siad, "I almost look at these slander charges (against Amanda) as harassment." And he and Mellas described how they keep their spirits up despite all the family's been through: