A federal grand jury in Knoxville, Tennessee returned an indictment on May 7, charging Regan Darby Prater, 27, with arson for firebombing the Highlander Center, a nonprofit research and education center in New Market, Tennessee; and with carrying an explosive device during the commission of the arson. Prater appeared in court today before U.S. Magistrate Judge Jill E. McCook and entered a plea of not guilty to the charges in the indictment. He was held pending trial, which has been set for July 15 in United States District Court, in Knoxville, Tennessee.