Seattle (CNN) -- A libel case against the parents of Amanda Knox "feels very personal," the mother of the American student convicted of murder in Italy told CNN.
"I wouldn't say the Italian justice system (is after us.) I would say a few people in Perugia, definitely," Edda Mellas said, referring to the central Italian city where Knox was tried for the 2007 killing of her British roommate Meredith Kercher.
She cited a radio commentator who suggested the authorities' attitude seemed to be: "Maybe if we keep at them they'll go away or go bankrupt or whatever.
"But it's not stopping us," she said.
"It's all about truth and justice and we have done nothing wrong," she said.
"Amanda's allowed to tell her story and she's been saying it hundreds of times since she was arrested," Mellas said. "When we get asked, 'What did Amanda tell you?', we tell the truth: Here's what Amanda said. And that's why we're being charged."
Mellas and her ex-husband, Curt Knox, were indicted Tuesday on charges of libeling police in Perugia, she and the family's Italian attorney said.
In a 2009 interview in the Sunday Times of London, they said that their daughter "had not been given an interpreter, had not received food and water, and had been physically and verbally abused" by police after her arrest for the murder of the exchange student, according to Italy's ANSA news agency.
They also said police struck her and told her "things will get worse for you" if she requested an attorney.
"Yes, I am going to trial for libel ... along with one of my lawyers and a group of journalists," Mellas told CNN Tuesday.
"We are very upset by this decision," said Luciano Ghirga, Amanda Knox's attorney who represents her family in this case. "We worked toward a dismissal because there was no intent" on the part of Knox's parents to libel the police, he said.
The indictment says their claims were "contrary to the truth," according to ANSA.
"We knew this was coming for a while," Mellas said. "I got served my papers a year ago, back over a year ago, so I knew, we knew this was coming."
She said she would attend hearings in her own trial only if she happened to be in Italy anyway.
But she would continue to fight the charges for fear she could be arrested in Italy if she does not, she said.
"We have to jump through the hoops until I know that I will never have to go back to that country again," she said.
"I think our case may go years, depending on what happens in Perugia. If we're found guilty we will appeal, even if it means going to the Supreme Court," she said.
She said fighting the charges had been financially draining.
"I think we've mortgaged just about everything we can mortgage, but there's been very kind people who have sent donations to help pay for Amanda's defense," she said.
A hearing in the parents' case is set for July 4, Ghirga said.
"These are old charges," said David Marriott, spokesman for the family. "They've been around since 2009." The story in question was published in 2008, he said, and Knox's parents were repeating what their daughter had told them.
The indictment, Marriott said, finalizes the charges the prosecutor had filed and is "nothing surprising."
Knox's parents' focus is not on their case, he said, but on her appeal of her conviction, which is under way. There is a break in the proceedings for experts to retest forensic evidence, he said.
"This is, I guess you'd call it, a bit of a minor distraction," Marriott said.
Knox, 23, was sentenced in December to 26 years in prison for Kercher's death at the villa the two shared in Perugia, the central Italian town where both were students.
Kercher, 21, was found dead in November 2007, semi-naked with her throat slashed. Knox and her former Italian boyfriend, Raffaele Sollecito, were both found guilty of the murder.
Sollecito is serving a 25-year sentence. A third person, Rudy Guede, a drifter originally from the Ivory Coast, was tried separately and is serving a 16-year prison sentence.
The forensic experts retesting evidence as part of Knox's appeal must conclude their analysis by May 9 and their results are to be presented on May 21 to a jury composed of two judges and six citizens.
Evidence being retested includes a knife found in Sollecito's apartment with Knox's DNA on the handle and what Perugia prosecutors say is Kercher's DNA in a tiny groove on the blade. The prosecution contends that the knife was used to stab Kercher in the neck and that it had been cleaned. The DNA matter attributed to Kercher consists of flesh, not blood, they say.
The sample, however, was so small that forensic scientists investigating Kercher's murder were not able to double test it in accordance with international forensic science norms, which Knox's legal team says raises doubts about its validity.
The second piece of evidence the forensic experts will test is the tiny metal clasp from Kercher's bra, which was cut from her body after her slaying. Forensic scientists in the investigatory phase determined that Sollecito's DNA is present on the metal clasp. The clasp was identified on an investigatory video on November 2, 2007, when Kercher's body was found. But the clasp was not collected until nearly six weeks later, giving the defense cause to question whether the sample may have been contaminated.
The court is not expected to make a final ruling on the appeal until next summer.
CNN's Drew Griffin, Hada Messia, Ashley Hayes, Todd Schwarzschild and journalist Barbie Nadeau contributed to this report.