Today, Regan Darby Prater, 28, currently of Tullahoma, Tennessee, entered a guilty plea to one count of arson and one count of attempting to provide material support to a foreign terrorist organization. Prater pleaded guilty in the U.S. District Court for the Eastern District of Tennessee at Knoxville. Sentencing has been set before U.S. District Judge Thomas A. Varlan for Sept. 9, in Knoxville.