MINOT, N.D. — A South Dakota man accused of sexually abusing two girls while he was living at Minot Air Force Base in North Dakota has pleaded not guilty.

Thirty-nine-year-old Thad Richard, of Manderson, South Dakota, allegedly abused the girls between 2007 and 2009 at a residence on base. He’s accused of having sex with one of the children and fondling the other.

Richard on Thursday pleaded not guilty to three counts of felony gross sexual imposition. He could face life in prison if convicted.

His trial was not immediately scheduled.