In criminology, a disorganized offender, also sometimes called a maniac, is a classification of serial killer.
The distinction between "organized" and "disorganized" offenders was drawn by the American criminologist Roy Hazelwood.
The disorganized offender is usually of low-average or below average intelligence. They often have poor work ethic and are apt to be regularly fired from or reprimanded at work; in the cases where a disorganized offender has a steady work ethic, they work blue collar jobs or jobs which require little or no use of reasoning or intelligence. They are socially inadequate and possess little or no interpersonal skills; most disorganized offenders have never been married or in a serious relationship. Although a disorganized offender may claim to be heterosexual, evidence will usually suggest that they are either a virgin or that their sexual conquests have come in relation to a paraphilia, such as necrophilia, bestiality, or pedophilia. Some disorganized offenders have exhibited homosexual tendencies, but in such cases, any homosexual contact they may have had will usually be either as a symbolic act of dominance or as an offshoot of one of their paraphilias. They most often live alone or with a family member.
Disorganized offenders have an innate fear or anxiety in regard to people, especially strangers, and usually live in a complex delusion that they have constructed in their own mind. Ed Gein, for example, exhumed the corpses of women who he believed reminded him of his mother and consumed parts of them because he believed that he could preserve his mother's soul inside of his own body, going so far as to create a "female suit" made of human flesh that he would wear when assuming his mother's identity.
Disorganized offenders, lacking confidence and the skills necessary to plan a crime, do not venture far from their homes when committing murders. Their victims are either chosen at random or are people they know personally. The murder is violent, brutal, and sadistic; the disorganized offender uses overkill. A disorganized offender may stab his victim dozens of times even after he or she is dead.