A high school basketball coach in Iowa has been arrested on charges that he filmed his players disrobing in a hotel bathroom.

Greg Stephen, co-founder of the Amateur Athletic Union traveling team, the Iowa Barnstormers, was taken into custody Tuesday by the FBI on child pornography charges after giving a full confession.

Stephen was fired by the Barnstormers last month when investigators searched his home and cabin. According to a report from a local CBS affiliate, a criminal complaint alleges Stephen's former brother-in-law came across a USB recording device in a bathroom while doing remodeling work in Stephen's home last month. The USB stick contained digital video files that showed teenage boys disrobing and entering and exiting a hotel bathroom shower. 

Investigators later found more than 100 clips of three players, ages 12, 13, and 14, that Stephen admitted were made in a hotel room in Lombard, Illinois, during a January trip to watch a Chicago Bulls game. 

Stephen said that he made the videos to look at “how much taller the kids were going to get and how developed they were," adding that he did so partly by observing their genitalia and body hair. Later he admitted that he was “maybe a little bit” aroused by watching the videos.

Stephens is being charged with transporting child pornography, which carries a sentence of 15 to 30 years in prison.