A Long Beach man was sentenced Friday morning to 20 years in federal prison for sex trafficking operations that involved threatening and physically beating victims to force them into prostitution, according to the U.S. Attorney’s Office.

Roshaun Nakia Porter, 39, was sentenced for running a sex trafficking operation that victimized young women whom he forced to work as prostitutes.

David Bowdich, the assistant director in charge of the FBI’s Los Angeles Field Office said in a statement that Porter recruited unsuspecting victims as sex slaves and promised them wealth and a better life. He then held them hostage by physically beating them and issuing death threats.

According to court documents, Porter conducted the scheme between 2010 and April 2012 in Orange County, where he exploited young women, including foreign nationals and U.S. citizens.

He would post advertisements for the women on craigslist.com, modelmayhem.com and seekingarrangements.com, and made fraudulent promises to the women of legitimate employment.

“Porter reaped substantial illicit profits by luring his victims into personal relationships with him and, thereafter, compelling them to prostitute and provide him the proceeds from their commercial sex acts,” according to the U.S. District Attorney’s Office. “To compel the victims into compliance, Porter used physical violence, psychological abuse, threats to harm the victims’ family members and other coercive means.”

Porter pleaded guilty in July 2014 to conspiracy to engage in sex trafficking by force, fraud and coercion.

“Porter masterminded a reprehensible sex trafficking enterprise that caused extreme trauma and lasting injury to victims,” said Acting United States Attorney Stephanie Yonekura in a statement. “Over the course of nearly two years, Porter victimized young women with flagrant lies, bogus romantic overtures and acts of violence as he forced them to give up their bodies for his profit. This conduct is intolerable and warrants the lengthy sentence issued today by the court.”

Porter’s co-defendant and protege in the operation, 40-year-old Marquis Monte Horn of Long Beach, was sentenced in October by Judge Staton to 78 months in prison after he pleaded guilty to conspiracy to engage in sex trafficking. According to court documents, Horn admitted that between December 2010 and April 2012, he recruited victims into Porter’s prostitution ring. Horn was also ordered to pay $69,719 in restitution to one victim of the sex trafficking operation.

In addition to the 20-year prison term, Porter was ordered by U.S. District Judge Josephine L. Staton to pay $866,244 in restitution to 10 victims.

Two other defendants pleaded guilty in connection with the case and are scheduled to be sentenced in the coming weeks, according to the U.S. District Attorney’s Office.