Updated

Attorneys for a Colorado man charged with killing an eastern Montana teacher say his mental disabilities make him unfit to stand trial.

The attorneys asked a state judge on Friday to commit 24-year-old Michael Keith Spell to a state facility for up to 60 days to undergo a mental examination.

The Parachute, Colo., man faces a felony murder charge in the death of Sherry Arnold, a Sidney High School teacher killed in January 2012 while on her morning run.

A co-defendant pleaded guilty under a deal with prosecutors. Spell could face the death penalty if convicted.

Court records in Colorado show Spell was declared incompetent by a judge in 2010 in a Garfield County drug case. His defense attorneys say he also has a prior diagnosis of mental disability.