Michael Spell, 25, of Parachute, Colorado, admitted his role in the strangling death of math instructor Sherry Arnold while prosecutors dropped a count of attempted kidnapping, in a reached plea agreement on Wednesday, according to the New York Daily News.
Spell is accused of killing the Montana teacher during a cocaine-fueled frenzy, The Associated Press reported.
Arnold, 43, vanished Jan. 7, 2012, after setting off for a pre-dawn run in her northeastern Montana home town of Sidney, according to the AP.
He pleaded guilty to murder on Wednesday as part of a deal in which prosecutors will dismiss a kidnapping charge in the case, court documents showed, according to the AP.
Prosecutors are recommending a prison term of 100 years for the crime of deliberate homicide, but would place no restrictions on Spell's eligibility for parole during that period, according to the deal, the Daily News reported.
Spell later told authorities he and Lester Waters, a friend from Parachute, had smoked crack cocaine and were driving through Sidney toward neighboring Williston, North Dakota, for oilfield jobs when Arnold jogged by, according to the AP. Waters then ordered him to pull her into their Ford Explorer, according to Spell's account.
Spell told investigators that Waters "choked her out" in the back seat, but prosecutors alleged in court documents that Spell strangled her, the AP reported.
Arnold "lay dead inside the vehicle and under a blanket" while the men drove to Williston, where they threw her clothing into a dumpster and bought a shovel to bury her body in a shallow grave outside town, a Montana prosecutor said in a sworn statement, according to the AP.
Waters, 50, pleaded guilty last year to a charge of deliberate homicide in Arnold's death, but has not yet been sentenced, the AP reported. Spell's attorney's sought to prove Spell was unfit for trial because of mental deficiencies.
