(AP) — A Montana judge will consider a plea agreement Wednesday that calls for a Colorado man to plead guilty to killing a high school teacher and burying her in a shallow grave in the Bakken oil patch. The disappearance of Sherry Arnold when she went out for a jog in January 2012 shook this town of 6,200 near the North Dakota border and shone a harsh light on the darker side of the oil boom on the Northern Plains. The plea deal with prosecutors filed Tuesday calls for a 100-year sentence for Spell and dismissal of an attempted kidnapping charge. Defense attorney Al Avignone said he will ask for Spell to be sentenced to the state health department, which could allow him to serve his time in a facility for the mentally disabled. Experts for the state and defense have testified that Spell is mildly mentally disabled.