Two Wisconsin girls accused of stabbing a classmate to please a fantasy character called Slender Man are mentally fit to stand trial on attempted homicide charges, a judge ruled Thursday.Experts for the state concluded that both girls would be able to assist in their own defenses but their attorneys disagreed with the findings. Waukesha County Circuit Judge Michael Bohren sided with the state during back-to-back hearings to decide the issue Thursday.During the first hearing, the 13-year-old girl watched quietly as experts explained why they thought she was or wasn't fit to go on trial. Wearing a black pantsuit and shackles, she spoke only to tell the judge that she believed she wasn't competent.Psychologists Anthony Jurek and Michael Caldwell testified for the defense that they interviewed the girl several times. They said she's clearly intelligent but has trouble making decisions when she's bombarded with information. She doesn't understand the nuances of the criminal justice system, such as the risk of turning down a plea bargain, they said.Psychiatrist Robert Rawski testified for the state that he believed the girl was highly capable. Ted Szczupakiewicz, an assistant district attorney, said judging by the two defense psychologists' reports the girl answered their questions about the legal process correctly.Bohren said that by all accounts the girl is highly intelligent."I'm satisfied that the issues of age and maturity do not override her competency," he said. "She's competent to make the decisions that have to be made."The judge ordered the other girl to undergo mental health treatment in August after a psychologist testified that she claimed to see and hear unicorns, Slender Man and Lord Voldemort, the villain from the "Harry Potter" series. Psychiatrist Kenneth Casimir generated a report in November, however, that found her mental state had improved.Bailiffs led that girl into the courtroom for her hearing in shackles, too. She wore black leggings and a zip-up sweatshirt over a Batman T-shirt.The proceeding lasted only a few minutes. Her attorney, Anthony Cotton, told the judge the girl suffers from schizophrenia, but he declined to challenge Casimir's report, offering the judge no explanation. After the proceeding, he told reporters that he felt he didn't have a strong basis to challenge the report.Bohren said he thought Casimir's report was credible and deemed the girl competent to stand trial.The judge set a joint preliminary hearing, the point in the legal process where he will have to decide whether enough evidence exists to proceed to trial, for February.Prosecutors have charged both girls with attempted first-degree intentional homicide in the attack in May in Waukesha, a city of 71,000 about 15 miles west of Milwaukee. They say the girls plotted for months to kill classmate Payton Leutner, luring her to a wooded park after a sleepover and stabbing her 19 times. After her attackers left, Leutner crawled through the woods to a sidewalk where a bicyclist found her and called 911.The two girls charged in the case were found walking toward a national forest where they said they believed Slender Man lived in a mansion.All three girls were 12 at the time. The first girl that Bohren found competent Thursday has since turned 13.Press isn't naming either defendant because their attorneys have said they may still try to move their cases into juvenile court, where proceedings are secret.