The sex-trafficking trial of Otis D. Washington is an eye-opener for many reasons, beginning with its alleged scope and duration.

Washington, 29, of Ramsey County, is charged with coercing more than 10 women and girls into prostitution for two years — with the help of family members, including his brother and two uncles.

Representing himself at his trial last week, Washington arrived for opening statements dressed in his jail-issued orange jumpsuit.

What stopped me, though, was news that his brother’s ex-girlfriend also faces charges.

I’m always surprised to hear about women who are perpetrators in sex rings. Turns out I shouldn’t be.

“Sex trafficking is an equal-opportunity crime,” said University of Minnesota Law School Prof. Mark Kappelhoff. Before coming to the U, he spent 15 years as a federal prosecutor.

“We’ve seen men and women prey upon vulnerable victims,” he said. “Sadly, we’ve seen family members, mothers. There may be a little more trust. Maybe it’s easier for women to exploit another woman.”

But he and others emphasize that every woman comes with her own story. For most, it is a story of personal victimization.

“The common story line about these women is that they started being prostituted in their teens,” said Ramsey County Attorney John Choi, noting that the average age of entry into prostitution is 12 to 14. Only later do these girls sometimes move into work as traffickers themselves, he said.

“A young girl doesn’t grow up to want to be a trafficker,” Choi said. “She is coerced through acts of violence to be kind of the recruiter.”

Equally insidious is when she is coerced through a promise of love.

In the Washington case, for example, a 20-year-old female victim testified that Washington wooed her after they met at a bus stop in downtown St. Paul. She moved in with him soon afterward and believed that Washington truly cared for her. Then he began to physically and verbally abuse her, she said, ultimately forcing her to prostitute herself or find other victims.

In the criminal complaint, she said Washington and his family act like boyfriends, suggesting, “If you really love me, you’ll do it.”

For a small number of women, participating in sex trafficking is a business proposition. “This is a market-driven activity,” said Lauren Martin, director of research at the U’s Urban Research Outreach-Engagement Center.

Martin, whose research includes a study of 135 women in north Minneapolis involved in prostitution, urges us to be careful to label others too quickly, as “past victimization is critical to how and why women are involved.”

Still, she said, “no humans are immune from getting involved in an exploitive avenue for making money.”

In May, Tabbatha L. Olson of Duluth was charged with aiding and abetting sex trafficking, along with a 32-year-old man. She landed in the St. Louis County jail.

In the Washington case, charges say, the female defendant taught others how to post ads on adult-oriented websites.

But the highest-profile story of late is that of Bionca Elizabethhelen Mixon, who was charged with playing a key role in the seven-day kidnapping of a 17-year-old Iowa girl forced to have sex with about 30 men in a St. Paul hotel room in January 2012.

“Mixon was doing most of the coercing,” Choi said, noting that the girl was “basically enslaved. She threatened the girl and beat her up.” When Mixon and her boyfriend, Tyree Erik Jones, left the hotel one day, the girl scribbled a note: “If you find me dead today, Biyonca Mickle [sic] did it. Tyree Erik Jones was involved.” This, Choi said firmly, “is a female who had crossed the line,” from being tangentially involved to being “substantially involved.”

“We have to do right by the victim and the community and enforce our laws,” said Choi, noting that prosecutions against traffickers doubled statewide from 2011 to 2012.

Yet the Mixon case demonstrates just how complex the work of prosecuting, or not prosecuting, female traffickers can be. Breaking Free, a Twin Cities area program that advocates for girls and women involved in sex trafficking, supported Mixon.

“She is a victim,” said Vednita Carter, Breaking Free founder and executive director. “Understanding where she came from, you learn that her choices were very limited. She was very involved, but the reasoning was a lot different from the guys. What was she facing if she didn’t do it?”

Mixon pleaded guilty and got a year in jail.

Carter and Choi do agree that goodwill between women’s advocates and law enforcement has increased, with a growing willingness to consider the complexities and nuance of human behavior. “As part of a developing case, we may consider dismissing the charge as we learn more information,” Choi said.

Carter appreciates that. “We are more of a team now, although we are always going to have our differences, such as the Mixon case,” she said. “We are at a point where we can sit down and talk about things. We’ve come a long way.”