After six weeks of trial, a sprawling international probe that swept up 39 people accused of trafficking hundreds of women from Thailand to be sold for sex in the United States will soon be in the hands of federal jurors.

Jurors on Tuesday afternoon will begin considering charges against five remaining co-defendants accused of holding "higher level" roles in a lucrative business that prosecutors said winded on for more than a decade.

Trial began Nov. 5 in St. Paul before Senior U.S. District Judge Donovan Frank and included weeks of testimony from federal agents and multiple women who described working long hours having sex with numerous men each day to pay off "bondage debts" they owed their traffickers for help coming to the U.S.

Prosecutors say the defendants — arrested as part of an international law enforcement operation dubbed "Bangkok Dark Nights" — helped the women fraudulently obtain visas and lied to them about the size of their debts, often more than $40,000 to $60,000.

"This was modern day sex slavery," Assistant U.S. Attorney Melinda Williams told jurors Monday, the first of two days of closing arguments before Frank began instructing jurors on the case mid-Tuesday.

On trial in St. Paul is Michael Morris, aka "Uncle Bill," 65, of Seal Beach, Calif.; Pawinee Unpradit, aka Fon, 46, of Dallas; Saowapha Thinram, aka Nancy or Kung, 44, of Hutto, Texas; Thoucharin Ruttanamongkongul, aka Noiy, 35, of Chicago; and Waralee Wanless, aka Wan, 39, of the Colony, Texas.

Morris allegedly ran several houses of prostitution in California and allegedly worked closely with Unpradit, who prosecutors said had a bondage debt of her own and funneled women to work at Morris' houses.

Like Unpradit, Thinram also allegedly began as a victim of the organization before going on to opening her own business in Austin, Texas, after she paid off her bondage debt, according to charges. Her husband, Gregory Kimmy, has since pleaded guilty for his role in helping Thinram run the house.

Charges against all five include conspiracy to commit sex trafficking, conspiracy to use transportation for prostitution, conspiracy to launder money and conspiracy to use a "communication facility" — such as phone or internet — to promote prostitution. Morris is also charged with sex trafficking by "use of force, threats of force, fraud and coercion."

Prosecutors say the ring relied on co-conspirators to recruit victims in Thailand, commit visa fraud and arrange travel to the U.S., where traffickers would hold bondage debts over victims who would be shuttled between various "houses of prostitution" throughout the country, including in the Minneapolis-St. Paul metro area.

The women were set up at high-end apartment buildings or lesser-quality "spas" where prosecutors say they were made to engage in "all-day, everyday commercial sex" and could use just 60 percent of their earnings to pay down their debts with the rest going to "house bosses" who allegedly used the funds to cover costs of business like renting apartments and paying to advertise the women's services online.

Attorneys for the five on trial have not disputed that their clients participated in the sex trade, noting that prostitution is not a federal crime. Morris' lawyer, Robert Sicoli, freely described Morris' role in running several houses of prostitution in California.

"And he ran them ethically," Sicoli told jurors Tuesday, arguing that the women who passed through Morris' houses were treated fairly.

The defense has argued that the women were willful participants in selling themselves for sex, citing examples of women continuing to have sex for money well after they paid down their debts.

The attorneys also closed their cases by again assailing the credibility of several key government witnesses who described being victimized by the organization. Lawyers said the women lied to jurors and to the government about the extent of their previous sex work before coming to the U.S.

Paul Engh, Thinram's attorney, displayed photos of one woman, known as Amy, who posed with her wealthy husband on numerous sightseeing trips across the U.S. at the same time she has said she was still under a large bondage debt.

"Could she have conned you? In fact, she did," Engh said.

Bruce Rivers, Wanless' attorney, argued that many of the women in the case were sex workers before coming to the U.S. and that they agreed to travel here to make money to send back to family in Thailand.

"If the debt was OK with them then it is not coercive," Rivers said. "They talked to other women; they knew the score before they got on the airplane."

Daniel Gerdts, whose client, Unpradit, had a long history of her own of participating in sex work, told jurors there was no evidence Unpradit assumed she or her colleagues were working against their will.

"Being a sex worker from Thailand does not mean you're part of some global conspiracy to use force, fraud or coercion to compel women or men to engage in prostitution," he said.

But Williams described as "fraud 101" evidence that defendants charged women debts well in excess of what they were told it cost to facilitate their arrival in the U.S.

Other bosses in the case held on to victims' passports, Williams said, and threatened to harm their families back home if they tried to flee the business.

"What the defense wants you to do is to call this something different than what it was," Williams said Tuesday in her final statements to jurors before they were to deliberate. "What they're basically begging you to do is to call this prostitution. ... What was this? What was this? It was human trafficking."

Stephen Montemayor • 612-673-1755 Twitter: @smontemayor