A Utah truck driver kept sex slaves in his semitrailer for months at a time while he traveled the country, filing down their teeth, forcing them to alter their appearance and beating them until they nearly passed out, authorities said.

Timothy Jay Vafeades, 54, made an initial appearance Wednesday in U.S. District Court in Fargo, N.D., and will now be transferred to Utah for further proceedings.

The charges against him include kidnapping, transportation for illegal sexual activity, and possession of child pornography, and could bring a life sentence if he is convicted. His public defender, Richard Henderson, could not be reached for comment.

An arrest warrant filed Tuesday in Salt Lake City claims Vafeades kidnapped a 19-year-old female relative who had come from Florida in May 2013 to work with him on his truck, the “Twilight Express.”