Thomas Kirch, 27, who had been serving in Germany, and his mother, Gwen Kirch, a music teacher at St. Pius X Catholic School, are accused of setting the fire in the 7000 block of Eastwick Lane in April 2007.

David Kirch, Gwen's husband and Thomas' father, died in the blaze.

During an initial court appearance Friday morning, Thomas Kirch pleaded not guilty to three counts of arson resulting in serious injury or death and one count of conspiracy to commit arson, RTV6's Derrik Thomas reported.

Thomas Kirch and his mother, who face the same charges, weren't accused in the arson until September 2011. Prosecutors have been trying to arrange for Thomas Kirch to return to the country since then.

"They did not fight. The internal workings of the military process for bringing him back are complicated," said Marion County Deputy Prosecutor Ross Anderson. "They did their best to get him back her as quickly as they could."

Thomas Kirch, who appeared in uniform at his hearing, will be stationed at Fort Knox, Ky., while he awaits trial.

Court documents indicate that investigators found gasoline containers from the garage and that accelerant was poured on the stairs and in several rooms. Evidence was also gathered from a computer that was damaged in the fire.

Kirch and his mother will be tried together. The trial has been scheduled for Oct. 29. Each count carries a 20- to 50-year sentence, if convicted.

Gwen Kirch was on paid administrative leave from her job at St. Pius. Thomas Kirch was released on $75,000 bond, but his movement is restricted by the military.