North Dakota's Supreme Court threw out a murder plea by a man who was accused of killing a former girlfriend, setting her body ablaze and leaving it to smolder in a Towner County roadside ditch.

Police had no reason to stop Steven Torkelsen and search his pickup and camper soon after the body of Rebecca Flaa was discovered on June 27, 2004, Chief Justice Gerald VandeWalle wrote in the court's majority opinion Tuesday.

Torkelsen agreed last year to make a conditional guilty plea to murder in connection with Flaa's death, while reserving his right to challenge the search of his truck and camper. Northeast District Judge Lee Christofferson sentenced Torkelsen to 50 years in prison, with 30 years suspended.

Torkelsen's attorney, David Dusek, said Tuesday that the case will now return to district court, where lawyers will argue about whether evidence in the case may still be used against Torkelsen.

"We're pleased with the decision, and we look forward to the next proceeding," Dusek said.

Lisa Beckstrom Gibbens, the Towner County state's attorney, could not be reached for comment Tuesday. The Ramsey County state's attorney, Lonnie Olson, declined comment, saying he had not reviewed the decision. Olson signed a Supreme Court brief for the prosecution in Torkelsen's appeal.

Shortly after a local farmer, Tom Belzer, found Flaa's body on fire in a county road ditch about eight miles east of Cando, Torkelsen drove up in his pickup and asked Belzer if he needed help, court filings say. It was just before 9 a.m.

Belzer knew Torkelsen, and told him to leave, and he did, court documents say. Belzer thought it was odd Torkelsen did not even acknowledge Flaa's smoking body, only a few feet away.

Police later issued a bulletin for Torkelsen's truck, and he was pulled over west of Cando less than five hours later. The Highway Patrol officer who stopped Torkelsen did not see him violating any traffic laws, even though he observed Torkelsen for almost 15 miles, court filings say.

Torkelsen was driven about 28 miles to Cando for questioning, and advised of his right against self-incrimination. Police say during the interrogation, he agreed to searches of his truck and camper and provided a genetic sample.

Police found blood in Torkelsen's trailer, and he identified a blood-spattered Florida Marlins baseball team jacket, found along the roadside, as belonging to Flaa, documents say.

Authorities said Flaa was a former girlfriend of Torkelsen's, lived in the area occasionally and was visiting Torkelsen when she died.

Authorities also found a marijuana cigarette and rolling papers in Torkelsen's trailer, and he was initially arrested for possession of marijuana and drug paraphernalia. He was charged with Flaa's murder on July 8, 2004.

VandeWalle, in the court's majority opinion, said police did not have a sufficient reason to stop Torkelsen's truck. He was not observed breaking any traffic laws, and there was not enough evidence to suspect he had committed a crime, VandeWalle wrote.