According to a statement from the United States Attorney's Office District of Idaho, Stewart allegedly had tried to persuade the girl, between November 10, 2010 and March 2011, to engage in sexual activity.
Federal officials said Stewart is being charged with sending numerous texts, messages online and even sexually obscene pictures.
Police arrested him March 3, at the Indianapolis Airport, where officials said Stewart was waiting for the girl to come off the plane. He allegedly had made the travel arrangements, to take her back to Illinois, and booked had booked a hotel room in Indianapolis.
If he's charged with attempted enticement, he could face ten years to life in prison, a $250,000 fine, and five years to life supervised release. If he's charged of attempted transfer of obscene material to a minor, he could face up to ten years behind bars, a $250,000 fine, and up to three years supervised release.