By Laura Zuckerman
SALMON, Idaho (Reuters) - A man who said the crack cocaine he was smoking "brought the devil out in him" was looking for a woman to abduct and kill before he strangled a school teacher who happened to jog near him in Montana, a prosecutor said in a sworn statement.
The first public details about how authorities believe that Sherry Arnold, 43, was kidnapped, slain and buried in a shallow grave, emerged in an affidavit filed in state court on Friday by Richland County, Montana, prosecutor Mike Weber.
Most of the account, Weber wrote, stemmed from a confession obtained from the younger of two men charged with kidnapping the woman, whom they encountered along a truck route on the outskirts of the northeastern Montana community of Sidney.
Arnold, a high school math instructor, vanished after setting out on January 7 for a predawn run, and authorities are still searching for her body.
Two men from the western Colorado town of Parachute, Lester Vann Waters, 47, and Michael Keith Spell, 22, were arrested last month and charged with aggravated kidnapping in connection with her disappearance. But little had been disclosed about the case against them before Weber filed his 12-page affidavit, which was posted online by the Sidney Herald newspaper.
Spell told authorities that Waters, in a crack-induced frenzy, ordered him to grab Arnold and pull her into the Ford Explorer they were riding in, forcing her to lose a running shoe -- later found on the truck route by police -- in the ensuing struggle, the affidavit says.
"Spell said Waters got into the back seat with the female and 'choked her out,'" according to Weber's sworn account.
The victim "lay dead inside the vehicle and under a blanket" while Waters and Spell drove to Williston, North Dakota, about 45 miles northeast of Sidney, where they threw her clothing into a dumpster before stashing her body in a rural area outside town, Weber said Spell told investigators.
The pair then went to a Walmart store to buy a shovel to dig her grave. Spell said Waters forced him to dig the hole -- from 2- to 3-feet deep -- where Arnold was buried, the affidavit says. He said the site was at the end of a tree row used as a windbreak, or shelter belt, near an old farmstead, according to the statement.
Spell said he later felt remorse when he saw posters of the missing school teacher, telephoned his family in Colorado and told them what had happened, then hitchhiked to Rapid City, South Dakota, the affidavit says.
Authorities identified Waters and Spell as suspects after a tipster on January 11 called a police hotline to say that Spell's girlfriend in Colorado said that he had told her that he and Waters "picked up a lady walking along the road, killed her, and then buried her," the affidavit says.
Authorities in North Dakota arrested Waters in Williston on January 12. They recovered a receipt in Waters' possession that showed a purchase at Walmart of a shovel, which was later returned to the store and subsequently retrieved by investigators, the court document said.
FBI agents on January 13 arrested Spell in Rapid City, South Dakota, where according to the affidavit, he confessed to the kidnapping and killing.
They were extradited back to Montana last week.
Spell told investigators that Waters had been smoking crack, which Waters told Spell "brought the devil out in him" and made him capable of doing anything, according to the statement. "Spell said that Waters began talking about kidnapping and killing a female," the affidavit shows.
On January 15, the FBI asked landowners in far northeastern Montana and in three rural counties of neighboring northwestern North Dakota to check shelter belts with mature or rotted trees for Arnold's body.
Court documents claim that Waters and Spell left Parachute, Colorado, a West Slope city known for oil shale exploration and extraction, to find work amid an oil and gas boom in the Sidney and Williston areas.
The suspected abduction and murder of Arnold, who colleagues described as a well-respected and well-liked teacher, has cast a pall over Sidney, a 5,000-population farming community coping with an influx of newcomers linked to energy production.
Firearms and pepper spray sales have been on the rise -- particularly among women -- in Sidney since Arnold's disappearance and presumed death, Sidney Mayor Bret Smelser said in a recent interview.
"Basically, we have a community of women afraid to go out a night," he told Reuters on Saturday.
(Editing by Steve Gorman and Greg McCune)