HELENA, Mont. -

A mentally disabled Colorado man accused of killing a Montana teacher is asking the state Supreme Court to reverse a lower judge's ruling that he is fit to stand trial.
    
Michael Spell is charged with the attempted kidnapping and murder of Sidney High School teacher Sherry Arnold, who disappeared during a morning jog in January 2012.
    
Lawyers for the 25-year-old Spell asked the state high court Friday to overrule District Judge Richard Simonton. The judge ruled in May that Spell's mental disabilities were mild enough that he could understand the case against him.
    
Defense attorney Al Avignone said in his petition that Spell is intellectually disabled, illiterate and has difficulty understanding language and articulating thoughts.
    
He says Spell would not be able to make decisions based on his knowledge of the case.