Sherry Arnold, a Sidney High math teacher missing since Jan. 7, was choked to death and is likely buried in a remote area near Williston, N.D., according to court documents filed late Friday in Richland County District Court.
The documents largely focus on the alleged confession of 22-year-old Michael Spell, of Parachute, Colo., one of two men charged with aggravated kidnapping in Arnold's disappearance, and describe a crack-fueled, seemingly random abduction of Arnold. The other man is 47-year-old Lester Van Waters, also Parachute, Colo.
Until Friday, few details of Arnold's disappearance or the case against the two men had been released since their January arrests.
According to the documents, Spell told investigators that he and Waters smoked crack cocaine on a two- or three-day trip to the area from Parachute, Colo., and that Waters began talking about kidnapping and killing a woman.
As they drove through Sidney, they spotted Arnold as she was jogging and Spell confessed to agents that they killed her, the affidavit states.
He allegedly said that Waters parked on the side of the road as Arnold got near and told Spell to grab her. The woman's shoe fell off as she was forced into the Ford Explorer Waters was driving, Spell told agents.
During the initial search for Arnold, one of the only publicly released clues was the discovery of one of her running shoes.
"Spell said Waters got into the back seat with the female and 'choked her out,'" the affidavit says.
After getting money at a Sidney grocery store, they drove to Williston with the woman dead under a blanket and threw her clothes into a Dumpster at a truck stop there that night before leaving the body in a rural area outside of town, the charging documents state.
The documents say they returned to Williston and bought a shovel at Wal-Mart and returned to where they'd left the body.
"Spell said Waters made him dig a hole two or three feet deep, and then they placed the female's body in the hole," the affidavit states. "Spell said the grave site was at the end of a shelter belt, which is a line of trees used as a windbreak, on an old farmstead in a rural, isolated area outside of Williston."
FBI agents later found a receipt on Waters for bread, bologna and a shovel purchased at the Williston Wal-Mart that same night. Through video surveillance tapes from the area, agents also confirmed that Spell and Waters, and their vehicle, were in the same Wal-Mart.
Video footage shows Waters returning the shovel to Wal-Mart a few days later and Spell was able to identify it as the one they used to bury Arnold, the documents said.
Four days after Arnold's disappearance, a tipster reported that a Colorado woman named April Cruz claiming to be Spell's girlfriend said he confessed to her that he and Waters had been smoking crack-cocaine and driving around when they picked up a woman along the road, killed her and then buried her body, according to the affidavit.
On Jan. 12, she allegedly confirmed that information to an agent with the Federal Bureau of Investigation, which took the lead role in the case a few days earlier.
Officers in Williston detained Waters later that day. Early the next morning officers in Rapid City, S.D., picked up Spell, who had hitchhiked there because he was afraid of Waters, according to court documents.
Waters allegedly told Spell that smoking crack brought out "the devil" in him and that he'd "kill Spell and his family if Spell ever told anyone what happened," the documents go on to say.
Her disappearance resulted in several massive searches by hundreds of people across the Sidney and Williston areas.
As of Friday evening, investigators had not located Arnold's body. They are asking the people in rural parts of northeastern Montana and northwestern North Dakota to watch their property for areas like the one described by Spell that may have signs of recently disturbed soil.
Williams County, N.D., Sheriff Scott Busching said Friday that multiple leads have come in as a result of that request, but so far none have panned out.
"We've checked a lot of spots but we haven't found anything yet," Busching said.
Both men were extradited from Williston, where they had been held, on Tuesday to Sidney, where a judge ordered them to appear in District Court on Feb. 28.
Waters has a lengthy criminal background in Florida, where he lived before leaving sometime after his most recent release from prison in August 2010.
Beginning in the late 1980s, he had several stints in jail in Indian River County, Fla., and served three state prison sentences between 2002 and 2010. Charges against him included possession of a firearm by a convicted felon, sale of cocaine, petty theft, burglary, failure to pay child support, contempt of court, resisting an officer and multiple counts of driving with a suspended license.
Spell has prior arrests in Colorado on charges of drug possession, contributing to the delinquency of a minor, sexual contact without consent, careless driving and driving without a license. Charges filed against Spell in a pair of 2007 arrests were later dropped, although it was unclear on what grounds.
The most recent charges came in 2009 after Colorado authorities said Spell asked a middle-school student to text other students and ask them if they wanted to buy marijuana.
He was scheduled to be arraigned in that case in January. But Spell was given permission by a judge to leave Colorado two days before Arnold disappeared, after claiming his brother had been in a car accident in Texas.
Associated Press reporter Matthew Brown contributed to this article.