Michael Winterbottom’s adaptation of Jim Thompson’s noir crime novel arrived at the BBFC with some pre-publicity buzz. The BBFC was already aware of the film’s reputation, due to the general strength of the violence and sex, and a specific scene in which the lead character viciously beats Joyce - a character played by Jessica Alba. The film follows psychopathic small town Sheriff Lou, played by Casey Affleck, who embarks on some increasingly violent sexual relationships. The key classification issues were: strong bloody violence; strong sadistic violence; sexual violence; sadomasochistic violence, and child abuse references, and the strong threat and menace accompanying some of these.

Several scenes contain very strong violence; the strongest occurs in a scene in which Lou repeatedly punches Joyce's face, causing terrible injuries. The scene has a sadistic edge and there is some focus on the infliction of pain and injury, and the victim's physical and psychological suffering. In addition, the emotionally volatile killer gives a sinister verbal accompaniment to all his crimes. It is clear that he is a misogynist psychopath, and the scene explores the possible pleasure and terror he feels on destroying, degrading and disfiguring a beautiful woman.

Later, when Lou kills another character, Amy, there is further very strong and realistic violence, but less focus on the infliction of facial injuries and more on her complete terrorisation and humiliation – including her urinating after she has been beaten.

With their affecting and visceral brutality, both scenes have considerable impact, and are made even more intense as they are viewed largely from the perpetrator's point of view.

There are also scenes in the film of strong sadomasochistic sexual activity and violence between adults, with some focus on the injuries caused by the BDSM activity (bruises, welts, cigarette burns etc). Other scenes suggest a child has been abused.

Although several scenes in the film are undoubtedly strong and impactful, with the potential to cause offence to some viewers, the presentation of complicated and disturbing ideas is permissible under BBFC Guidelines at 18. None of the portrayals of sexual or sexualised violence eroticise or endorse sexual assault or similar behaviour. Indeed, they are strongly off-putting, rather than encouraging any sort of viewer complicity.

The graphic violence and sadomasochistic sex are strong in tone and feel, but presented within an overall justifying narrative context which is carefully controlled by the film-makers. Although the film deals with moral ambiguity, the BBFC didn’t read it as ambiguous, because the clear focus is Lou's escalating depravity and the contradiction between his homely image and his private behaviour. It is clear that he is a psychopath rather than a character who encourages emulation. The BBFC determined that no material in The Killer Inside Me breaches UK criminal law, and the film does not pose a credible harm risk to viewers of 18 and over. The film was therefore passed at 18 uncut in 2010.