"[2][3] Lou Ford appears to be an unremarkable deputy sheriff in a small Texas town; beneath this facade, however, he is a cunning, depraved sociopath with sadistic sexual tastes.

Despite having a steady girlfriend, schoolteacher Amy Stanton, Ford falls into a passionate, sadomasochistic relationship with a prostitute named Joyce Lakeland.

Though Lou believes he has gotten away with the crime, county attorney Howard Hendricks becomes suspicious of his version of events, as well as his alibi, and a third person is suspected to be involved.

Lou denies that the letter is incriminating, but Plummer and Hendricks force him into a jail cell, where they try unsuccessfully to provoke a confession with audio of Johnnie's voice and pictures of Amy.

In 1976, the novel was adapted into a film of the same title, directed by Burt Kennedy and starring Stacy Keach as Lou Ford and Tisha Sterling as Amy Stanton.

A 2010 version written by John Curran, directed by Michael Winterbottom and starring Casey Affleck and Jessica Alba premiered at the Sundance Film Festival in January 2010, and was released in theaters later that year.

[5] C. Namwali Serpell has outlined a phenomenological, postcritical reading of The Killer Inside Me that exposes the limitations of purely ideological interpretations of the novel.