Updated

A Utah couple being investigated by authorities as part of a probe into the death of a 16-year-old girl will soon face criminal charges in the case, a defense attorney said Wednesday.

Alexis Rasmussen vanished Sept. 10 after babysitting for Eric and Dea Millerberg in North Ogden, about 40 miles north of Salt Lake City, according to police. Her body was found Oct. 18 off a highway.

Dea Millerberg, 37, appeared in court Wednesday on unrelated prescription drug fraud charges and was ordered held on $10,000 bail pending a Nov. 16 hearing. Her husband was sent to prison Tuesday for violating probation in a 2010 fraud case after authorities say he was found with heroin and Oxycontin and had failed to report to his probation officer.

Weber County Attorney Dee Smith earlier this week identified the couple as "persons of interest" in the teens' death, but declined to elaborate. Smith said autopsy results may take a month. He would only say that Rasmussen died in a house on or around Sept. 11 and that her body was moved to a grave near Interstate 84, about 35 miles from North Ogden.

Smith has not returned repeated telephone calls from The Associated Press.

Dea Millerberg's attorney, Michael Bouwhuis, said Wednesday Smith informed him that both Millerbergs would soon face charges in the teen's death that could range from body desecration to capital murder. Eric Millerberg's attorney didn't return a call seeking comment.

The victim's mother, fighting through tears during a Wednesday news conference, said she had never met Eric Millerberg but thought Dea Millerberg "seemed to be a mom like me."

"I had no idea they'd be capable of doing something like this," Dawn Miera said.

Authorities still have not said publicly the couple is responsible for the teen's death, but only that they were being investigated as part of the probe.

Bouwhuis said Dea Millerberg is accused of "doctor shopping" for the prescription drugs Oxycodone and alprazolam, an anti-anxiety medication.

On Sept. 10, Rasmussen was babysitting for the couple's two young children. At about 10:30 p.m. that night, the teen was seen with Dea Millerberg on surveillance video at a nearby all-night pharmacy, Miera said.

She said she also received text messages from her daughter about an hour later indicating she was back at the couple's home, and still babysitting because the Millerbergs had left to resume their date. It wasn't clear why they had returned to go to the pharmacy.

Miera said she told her daughter to stay the night because it was so late. The girl vanished soon after.

The Millerbergs told police that Rasmussen left their home before midnight to meet a friend, but police said that person never saw her.

Please click here for more from Fox13now.com