Deductive Offender Profiling

Deduction is about drawing logical reasoning and conclusions based on facts. By examining the crime scene and the victim in the case at hand, deductive profiling tries to draw logical conclusions about the offender in that particular case. For example, one might conclude that the offender has a certain size and strength if large, heavy objects were moved at the crime scene.

This type of profiling places great weight on the profiler's expertise in behavioral science and their ability to draw conclusions from the individual case. The deductive method thus starts from the individual's actions, and behavioral science experts build a profile of the offender from these. A strength of the method is that the profile is well suited to the individual case, but a weakness is that there is a risk of subjective judgments.

The FBI method

The FBI methodis a deductive profiling method developed during the 1970s by the FBI's Behavioral Science Unit (BSU). The unit was created to work on particularly serious and hard-to-solve crimes, such as serial murders and serial rapes. The method is still used today and is mainly aimed at unusual, extreme, and often very brutal crimes where the offender is assumed to have clear psychological problems.

An important starting point in the FBI method is that the work is carried out by teams rather than individual profilers, and that the profilers work closely with the police throughout the investigation. The method is used not only to create an offender profile but can also provide guidance on other parts of the investigation, for example how to approach a suspect during questioning or how to respond to messages from a potential offender.

Step 1: Gathering information

In the first step, as much information as possible is gathered. This includes, for example, police reports, crime scene photographs, witness statements, technical evidence such as DNA and footprints, and information about the victim. The aim is to build as complete a picture as possible of the crime and its circumstances.

Step 2: Classifying and organizing information

In the next step, the information is organized into meaningful patterns. Here the crime scene is usually classified as either organized or disorganized (chaotic).

An organized crime scene is characterized by planning and control. The crime appears deliberate and systematically carried out, and there is often little evidence such as DNA or fingerprints. The offender is often assumed to be intelligent, socially functional, and goal-oriented.

A disorganized crime scene, on the other hand, is more chaotic and impulsive. There is often a great deal of forensic evidence, and the crime appears to have happened spontaneously. The offender is often described as younger, more psychologically unstable, socially isolated, and sometimes struggling with substance abuse.

Today there is also talk of mixed crime scenes. A mixed crime scene contains traces of both organization and chaos. In these cases the offender may, for example, have been interrupted during the crime itself, which may have affected how it was carried out.

The classification made is used not only to describe the offender but also to determine how the police should act, for example during questioning. An organized offender can be approached more directly and factually, while a disorganized offender may require a more empathetic and adapted approach.

Step 3: Reconstructing the crime

In the third step, the sequence of events is reconstructed. Reconstructing the crime scene does not mean going to the location and acting out the events like an actor, the way it is often portrayed in films. Instead, it is about trying to understand the crime as a process in which at least two people, the offender and the victim, interacted. Investigators examine, for example, whether the victim was pursued or resisted, and how this may have affected the offender.

This step also identifies the offender's modus operandi (method), that is, how the crime was carried out. By analyzing this, it is sometimes possible to link several crimes to each other. In addition, investigators try to identify the offender's so-called signature, that is, the actions that are not necessary to commit the crime but that fulfill psychological needs, such as a need for control, power, or sexual gratification.

Step 4: Building the offender profile

In the final step, all the information is compiled into a profile of the offender. This profile may include details such as age, social background, education, occupation, military or police interests, relationships, lifestyle, and mental health.

The profile is then used by the police to compare against suspects, plan interview strategies, and gain a deeper understanding of the offender's behavior.

Criticism of the method

Although the FBI method has had a major influence on criminal profiling, it has also faced criticism. It is based on a limited empirical foundation, since it mainly focuses on very unusual crimes. Its scientific basis has also been questioned, since the method largely relies on intuition and experience rather than systematic research. There are therefore problems with reliability, validity, and subjective judgments.