thumb|Seal of the Federal Bureau of Investigation
In criminology, a disorganized offender is a type of serial killer classified by unorganized and spontaneous acts of violence. The distinction between "organized" and "disorganized" offenders was drawn by the American criminologist John Douglas and Roy Hazelwood. These profiles were also studied and modified in the FBI's Behavioral Science Unit located in Quantico, Virginia. By classifying these offenders into different categories, the FBI is able to track down offenders by studying their behavior and habits.
Offender background
The disorganized offender usually originates from a turbulent family situation and has dealt with assault from family members growing up. These offenders also commonly have obsessive thoughts and behave frantically, hence why the crime scenes for these offenders are messy.
Habits and crime patterns
Disorganized offenders do not venture far from their homes when committing murders, as they often lack consistent traveling methods (such as a car). The disorganized offender's actions are based mainly on spontaneity, which is why physical characteristics may not be as relevant to them in the moment. A common pattern found in disorganized crimes is that the victim is depersonalized as well.
During the crime, the offender may be using drugs or alcohol. Because the crime is unplanned, the murder weapon is usually found near the scene and there are fingerprints or DNA left on scene as well. A common method used by disorganized offenders is the "blitz" attack, which is where the offender uses extreme force on the victim to gain control over them. Disorganized offenders are not used to frequent social interactions, and therefore it is crucial to not immediately jump into the crime scene investigation and interrogation. Instead, approaching the situation in a roundabout way by discussing other events and then casually bringing up the main concern is another way to build trust. All of these individuals have been studied, and the patterns arising from their actions and their backgrounds highlight that they are disorganized offenders.