A man who once owned a Lawrence nightclub was sentenced to federal prison this week for running a sex-trafficking ring that lured vulnerable women to work as prostitutes.

On Monday in Topeka, U.S. District Court Judge Daniel D. Crabtree sentenced Frank Boswell to 46 months in federal prison — nearly four years — followed by five years of supervised release, according to court documents. Documents indicate Boswell was taken into custody following the judge’s ruling.

In July, Boswell pleaded guilty to one count of conspiring to sex traffic by force, fraud or coercion, according to his plea agreement.

Boswell, of Topeka, once was part owner in the now-closed Club Magic, 804 W. 24th St., in Lawrence.

In October 2015, Boswell was the lead defendant of seven people a grand jury indicted in the case — and cast in the indictment as the kingpin of the operation.

According to his plea agreement, Boswell admitted that:

He, along with others, operated a prostitution organization starting in 2010. At times, as many as 20 people worked as prostitutes in the ring, performing sex acts for money in Kansas and also being sent across state lines to do the same.

“Members of the organization targeted females who were vulnerable, with children, or who otherwise needed help and had no resources,” according to the plea agreement. “Members of the organization identified single mothers, females with drug problems, or females living in shelters.”

In one example, Boswell told a single mother living in a homeless shelter that he would “take care of her” if she worked for him. The woman believed she would not be able to leave the organization, but ultimately did leave after seeking help from an advocacy group.

Boswell maintained homes where he, the prostitutes and other conspirators lived, and used Internet-based escort sites to advertise the prostitutes’ services.

The prostitutes sent Boswell or other organizers text messages from their “appointments,” including when the customer arrived, when the appointment was “completed” and the amount of money made. The prostitutes turned over the money they made to Boswell, and many of them believed they could not spend money without his permission.

The building that housed Club Magic, 804 West 24th Street, is shown in this file photo from 2013.

In exchange for Boswell’s guilty plea to the one count, prosecutors agreed to drop more than a dozen other counts that had been filed against him, according to the plea agreement.

At his sentencing hearing, Boswell dressed in dark slacks, a dress shirt and vest, according to a report from KCUR. His relatives and supporters filled half the courtroom.

“Boswell performed hip-hop under the name Benefyshal and began his speech before the court with ‘mic check, one, two,’ drawing a small chuckle from the crowd and a little smile from the judge,” the radio station reported. “Boswell quickly turned serious, apologizing to his family for being a burden and to the entire state of Kansas for his years of human trafficking.”

“I have no excuses,” Boswell told the court, according to KCUR’s report. “I know it was wrong. I know it was immoral.”

Boswell’s co-defendants in the case, according to the original indictment, were former Club Magic manager Rachel Flenniken, Michaela Hekekia, Shannon Nelson, former Club Magic manager Sean P. Hall, Andre C. Rhoiney and Barry M. Johnson. Also known as “Franko,” Boswell was the “pimp” or “mac” of the ring, the indictment alleged.