MISSOULA, Mont. -- Richard Carpita faces four felony counts of promoting prostitution. Detectives claim at least five young women, from 16 to 19 years old, worked as prostitutes. They say all the women claimed that they were adults.

Investigators think Carpita and 21-year-old Anthony Brazington used Craigslist to solicit male clients, then cell phones to set up meetings. Missoula sheriff's detective T.J. McDermott says, "this occured primarily in Missoula. " But he says it also happened in Helena, Frenchtown, Idaho and Washington.

There's an arrest warrant out for Brazington. McDermott says, "so far we've identified at least six male clients who had responded to Craigslist and made arrangements to meet girls in Missoula to engage in sex acts for money.,"

Court records say two of the juvenile prostitutes told police the men would drive them to jobs and take the money they made. Another alleged prostitute said Carpita took half the money she made.

Sheriff's detectives led the investigation with help from city police, and a special task force that investigates internet crimes against children. City police Detective Guy Baker says, "there is no better example of the adage that this is the tip of the iceberg." Baker says exploitation of children on the internet is a "huge, huge problem."

Investigators say its possible other charges could be filed in the case.