A rural Louisiana couple accused of branding a Twin Cities woman with a bar code and keeping her as a sex slave believe their relationship with her was normal and can't understand why they're in trouble.

Authorities say she was held as a slave in rural Louisiana for at least two years until she escaped and was picked up last week near an interstate exit just outside the city of Natchitoches.

A logging chain connected to a bucket was secured around her neck, according to the Sheriff's Office. She was taken to a hospital for treatment of cuts and bruises. Authorities have not revealed her identity but her Facebook page says she graduated from Stillwater High School. Court records say she most recently lived in Blaine.

David Rodriguez Jr., 37, and Christina Harper, 39, both of Pleasant Hill, La., have been charged, accused of keeping the 54-year-old woman in a box and demanding sex from her.

"They see no remorse … and they believe we don't understand them. They are very comfortable and confident that they are doing the right thing," said Greg Dunn, chief investigator for the Natchitoches Parish Sheriff's Office.

Dunn said Rodriguez branded the woman with a bar code tattoo on the back of her neck to stake the couple's claim to the victim as property.

"Then with your iPhone, you scan the bar code and it shows on the website that [the woman] is registered with Rodriguez and Harper," he said. A bar code is prominently displayed on one of the victim's two Facebook pages.

A friend of the woman said Monday that she knew her friend, who is transgender, was in an "alternative relationship" with the couple but that she saw no hints she was at risk of being ensnared in a violent slave-like existence with the couple.

Cecilia Rogers said she socialized on occasion with Rodriguez, Harper and the woman during the few months Rogers and her family lived in northwestern Louisiana in mid-2012 before moving to New Mexico.

The three were romantically involved and lived in the same home, Rogers said, adding that she saw "no red flags" to suggest the woman would be abused or kept against her will.

Rogers even "liked" many computer-generated "Bitstrip" cartoons on the woman's Facebook page that portray violent submissiveness being acted out with the victim as one of the characters. One suggested the woman was living under the devil's control. However, Rogers continued, she didn't find those cartoons alarming at the time.

Dunn described the property as secluded and said that treatment of the woman went beyond what she was willing to tolerate as time went on. Authorities said she met the couple online.

Dunn said the woman is in protective custody at an undisclosed location in Louisiana and will get the psychological help she needs.

Beaten and chained

For a brief time, investigators say, the relationship was consensual. The victim was given daily chores such as serving meals, tending to animals, installing a swimming pool, digging trenches, removing fallen trees and performing sexual acts. She slept in a 3-by-5-foot wooden box.

Detectives said that if the victim failed to complete her work, she was disciplined by Rodriguez, Harper and Ambre Tubbs Lomas, 39, of Shreveport, La., who is also suspected of abusing the woman.

The discipline allegedly included beatings, carving initials into skin on the victim's backside, shootings with a stun gun and being doused with urine.

When the woman said she wanted to leave, she was chained outside in the woods with no food or water, detective Tim Key said. "And then she was put in a storage building in the yard."

A search of the home turned up 15 guns, a stun gun, four computers and video equipment. Two children, ages 15 and 16, were removed from the home and placed in temporary state custody. They are Harper's children from a relationship before Rodriguez.

Rodriguez and Harper were each charged with human trafficking, aggravated second-degree battery, second-degree kidnapping/false imprisonment and offenses against computer users. They and Lomas remained jailed Monday. Bond was set for Rodriguez and Harper at $635,000 each. Lomas was charged with second-degree kidnapping/false imprisonment and aggravated second-degree battery. Her bond was set at $525,000.

The Associated Press contributed to this report. Paul Walsh • 612-673-4482