Jury to decide defendant's mental health in Slender Man attack

MADISON, Wis. (AP) -- A Wisconsin jury this week will begin weighing whether a girl accused in the stabbing of a classmate to please the horror character Slender Man was mentally ill at the time.

Prosecutors say Anissa Weier and Morgan Geyser lured Payton Leutner into a Waukesha park and stabbed her 19 times in 2014. All three girls were 12 at the time.

Weier pleaded guilty in August to attempted second-degree homicide but maintains she's not responsible due to a mental disease or defect. Attorneys on both sides will begin selecting jurors on Monday to decide whether she was suffering from a mental defect.

A plea agreement calls for Weier to spend at least three years in a mental hospital if she's found to have been mentally ill and 10 years in prison if she's not.