Prosecutors believe modern witchcraft drove a Gold Bar man to kill his girlfriend, dismember her body and scatter her remains around Snohomish County.

Prosecutors outlined the gruesome details in the opening statements at the trial of Eric Christensen on Tuesday. Christensen has been charged with first-degree murder in the death of Sherry Harlan of Everett.

Christensen met Harlan through the Internet, and the two later moved in together.

"And we know this is a significant relationship, because Eric introduced her to his friends. He introduced her to his church," said defense attorney Kathleen Kyle.

Christensen told detectives the woman took a "blood oath" to break-off a relationship with another man. But when Christensen found text messages from an ex-boyfriend, he admits he flew into a jealous rage.

"In ancient times, people who broke blood oaths were sometimes killed," Christensen told investigators. He has denied any involvement in her death, however.

But prosecutors believe Christensen not only killed Harlan, but also plotted her murder. Investigators said Christensen went to great lengths in an attempt to cover up the crime, ripping out the carpet, bleaching the crime scene and mutilating the body to further hide evidence.

The defense attorney says there's no evidence of a premeditated murder.

"(Harlan's death is) terrible, terrible for many reasons," Kyle said. "But the dispute in this case is that the terrible reasons that this crime was tried to be covered up is not evidence of premeditation."

Harlan was reported missing Jan. 5 after she failed to show up for her job at the Alderwood Mall JCPenney store.

Prosecutors called to the stand one of Harlan's co-workers, who said she thought it strange when Harlan failed to show up for several of her shifts.

"And I thought, 'OK, well, something's got to be wrong here, because she would never go all those days without keeping in contact with anybody,"' said Teresa Remtko.

Harlan's burned-out 1989 Nissan Sentra was found Jan. 7 in the Reiter Pit area near Gold Bar. Detectives later said human remains were found inside the car.

Harlan's mother, Cheryl Thomas, said the murder victim was "the love of everybody's life, a joy to have around."

"Even when she was down, she never showed that she was down. She was just a really good person, a good person," Thomas said during a previous interview with KOMO News.

During the initial investigation, detectives began focusing on Christensen based on information from friends and neighbors who said Harlan told them her boyfriend had beaten her before. She told friends she was afraid to break up with him for fear he would come after her and kill her.

Another neighbor reported hearing yelling and fighting on Jan. 2 that appeared to come from Harlan's apartment.

On Jan. 6, detectives searched Christensen's home and car and discovered bloody clothing that appeared to belong to him. He also had numerous scratches on his face, forearms, shoulder and lower back, and a stab wound on his right knee.

Christensen initially was arrested and booked Jan. 7 into the Snohomish County Jail for failure to register as a sex offender. He has a 1990 conviction in Oregon for first-degree sexual abuse and is classified as a Level 1 sex offender. He was later charged with second-degree murder, which was upgraded to first-degree murder.

The trial is expected to take two weeks. The prosecutor has a long list of witnesses to call. The defense attorney hasn't said whether she plans to call Christensen to the stand.