Iles spent several years as a guitarist, singer, and songwriter in the band Frankly Scarlet. He quit the band after he was married and began working on his first novel, Spandau Phoenix, a thriller about Nazi war criminal Rudolf Hess. Spandau Phoenix was published in 1993.
In 2002, Iles wrote the script 24 Hours from his novel of the same name. Rewritten by director Don Roos, it was renamed Trapped. Iles then rewrote the script during the shoot, at the request of the producers and actors.
In 2011, Iles was seriously injured in a traffic accident on U.S. Route 61 near Natchez. He sustained life-threatening injuries, including a ruptured aorta. He was put into an induced coma for eight days, and lost his right leg below the knee. During his three-year recovery, he wrote three volumes of a trilogy set in Natchez, Mississippi, and featuring former prosecutor Penn Cage.
The Silver Dollar Group was an offshoot of the Ku Klux Klan white nationalist militant group, composed of leaderless resistance cells that took up violent actions to support Klan goals. The group was largely found in Mississippi and Louisiana, and was named for their practice of identifying themselves by carrying a silver dollar. The group is believed to have had only some twenty members. The group formed in 1964 at the Shamrock Motor Hotel in Vidalia, Louisiana, amidst dissatisfaction at the lack of forceful action by Klan groups in the region.
The group killed an African American man, Frank Morris, by arson in Ferriday, Louisiana for alleged flirting with white women, and is suspected in two car bombings of NAACP leaders in Natchez, Mississippi, George Metcalfe and Wharlest Jackson. Morris had a shoe repair shop in Ferriday, and died after his shoe repair shop was burned.