A judge in Waukesha will decide today (Thursday) whether to accept a plea deal for the second and final suspect in the Slender Man stabbing case. Fifteen-year-old Morgan Geyser is expected to plead guilty to attempted homicide — and her plea agreement with prosecutors would immediately find her not guilty by insanity, thus sending her to a mental hospital indefinitely. Geyser would be spared from a trial unlike her codefendant Anissa Weier, who’s expected to get three years in a mental institution after a jury found her innocent by insanity. Both girls are admitting that they stabbed middle school classmate Payton Leutner 19 times in May of 2014 in allegiance to the online horror character Slender Man.