( CNN ) -- American student Amanda Knox , convicted last year of murdering her British roommate in Italy , was ordered Monday to face a new trial on slander charges , her lawyer Luciano Ghirga said . She and her parents are accused of defaming Italian police in the wake of her arrest for the killing of Meredith Kercher . Monday 's hearing determined that there is enough evidence to try her . The case involves her allegations that police mistreated her in custody . Her parents face charges for repeating Knox 's allegations . Her stepfather , Chris Mellas , called Monday 's ruling `` a forgone conclusion . '' He pointed out that Knox was facing a judge and prosecutor who had been involved in the case before . `` Was there ever hope for an unbiased ruling with this line up ? There never was any in our eyes , '' he told CNN . `` We will be asking that the case be ... moved to Florence '' because the family considers the court system in Perugia to be biased , he said . `` Amanda made a statement today in court and in that statement she was clear as to her position , '' he said . `` She never wanted to make unjust accusations . She only wanted to defend herself , and had the police recorded the interrogation , she would not be in this mess today , and her position and statements would be confirmed by those recordings . '' Mellas said Knox did not claim to have been `` beaten '' by police , but hit on the back of the head . Knox wore black pants and a dark green sweater for her court appearance in Perugia , Italy . She wore her short hair pulled back from her face . The defamation trial is set to begin May 17 , 2011 , Ghirga , the lawyer , said . Knox , 23 , is also planning an appeal of her murder conviction . The appeal is due to begin November 24 . Knox was sentenced in December to 26 years in prison for the murder of the British exchange student in Perugia , Italy . Kercher , 21 , was found semi-naked with her throat slashed in the house she shared with Knox in November 2007 . Knox and her former Italian boyfriend , Raffaele Sollecito , 26 , were both found guilty of Kercher 's 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 .
NEW : There was never hope of an unbiased hearing , her stepfather says . 26 years 's hearing determined that there is enough evidence to try her . The Italian student convicted of killing her roommate is also accused of defaming police . She was sentenced 26 years to Monday in prison for killing Sollecito .