OCEANSIDE, Calif. -- A 23-year-old Oceanside man pleaded guilty Tuesday to forcing two teenage girls to work for him as prostitutes in Los Angeles and Orange counties, as well as Las Vegas.

Luther Gene Ray Jr. is expected to be sentenced to 100 months in federal prison when he goes back before U.S. District Judge Edward Rafeedie in Los Angeles on June 18.

Ray pleaded guilty to a pair of federal charges of sex trafficking children by force.

In his plea agreement, Ray admitted that he was a pimp to two minor girls in May 2004, and that he had them work as prostitutes in Southern California and Nevada.

The defendant required the girls to engage in commercial sex acts and to give him all of the money they earned, according to Assistant U.S. Attorney Caroline Wittcoff, who said Ray used coercive methods to ensure the girls would perform sex acts in exchange for money.

Prosecutors said Ray kept a close watch over the girls while they worked as prostitutes and made them believe that if they disobeyed him or broke one of his rules, he would physically harm them.