One of five people charged with forcing a runaway 16-year-old girl into prostitution and advertising her services on Craigslist pleaded guilty yesterday in federal court.

Brad Yick Kin Young, 21, of Aiea Heights pleaded guilty to one count of sex trafficking of a minor in a plea deal with the federal prosecutor. The charge carries a mandatory minimum prison term of 10 years.

In return for Young's plea, the government promised to drop two other sex trafficking charges against him when a federal judge sentences him in July. Young remains free on unsecured signature bond.

Young said he transported the girl in his car to a customer who paid to have sex with the girl, received a share of the proceeds and knew the girl's services were advertised on the Internet.

Another defendant, Spencer Miyahira of Aiea, is scheduled to plead guilty next month.

The other defendants are Marcus Xavier Arrington and Anthony T. Fuller, both 20, from Halawa Housing, and Jewel Aquino.

The girl, now 17, said Arrington forced her to have sex with customers for money during a 10-day period in December 2008 by threatening her with a handgun and giving her marijuana and cocaine, according to a federal indictment. The other defendants assisted in the prostitution operation by advertising the girl's services on Craigslist, transporting her to customers and providing security, the indictment said.

The girl escaped and told her mother what happened. The mother reported what happened to her daughter to an advocacy agency, which referred the case to Honolulu police.