The film is somewhat loosely based on the actual crimes attributed to an unidentified serial killer known as the Phantom Killer; it claims that "the incredible story you are about to see is true, where it happened and how it happened; only the names have been changed." The actual Phantom attacked eight people between February 22, 1946 and May 3, 1946 in or near the town of Texarkana, Texas, which is on the border of Texas and Arkansas. Most of the murders occurred in rural areas just outside Texarkana, in Bowie County, Texas, while the film has them occurring in Arkansas. However, the general outline of the murders largely follows the reality, with mostly minor artistic license taken. As in the film, the real killer was never identified nor apprehended.