A Wisconsin judge is deciding whether one of two 12-year-old girls accused of stabbing a classmate to please a fictional online horror character is mentally fit to stand trial.

The girl's public defender says she isn't, and notes a psychologist who examined the girl questions whether she'd be able to help with her defense. Waukesha County Judge Michael Bohren could make a ruling Wednesday.

Prosecutors say the two girls plotted to kill a classmate, who was stabbed 19 times during a walk in a park after a sleepover. She survived by crawling to a sidewalk where a bicyclist found her.

Bohren ordered the other suspect to receive mental health treatment after a psychologist testified that girl believes she can see things others cannot, including the online horror character Slender Man.