Forensic psychology addresses scientific questions about criminal actions, where the understanding of the actions leads to inferences about offender characteristics. Canter (2000) introduced the radex of criminality, the combination of quantitative and qualitative aspects of a crime. In addition, these quantitative and qualitative characteristics are viewed through the prism of development and change over time. The radex can be applied to any criminal behavior.
One of the most important investigative events of the last century was the creation of behavioral analysis units (BAUs) by the FBI. There are three BAUs. They are known not because of their ability to solve serial murders but because of their creation of a database, the Violent Criminal Apprehension Program (ViCAP), on which criminal justice professionals around the country and even the world have relied ever since.
Offender character assessment is the derivation of inferences about a criminal from evidentiary and psychological aspects of the crimes he or she has committed. For this process to move beyond deduction based on personal opinion and supposition to an evidence-based science, a number of aspects of criminal activity need to be examined, analyzed, and categorized. The notion of a hierarchy of criminal differentiation is introduced to highlight the need to search for consistencies and variations at many levels of that hierarchy. However, current research indicates that the key distinctions are those that differentiate, within classes of crime, between offences and between offenders. This also leads to the hypothesis of a circular ordering of criminal actions, analogous to the color circle, a radex.
The radex model, tested using multi-dimensional scaling (MDS) procedures, allows specific hypotheses to be developed about important constituents of criminal differentiation:
- Salience: MDS analyses reveal the importance of the frequency of criminal actions as the basis on which the significance of those actions can be established.
- Models of differentiation: The research reviewed mainly supports distinctions between criminals in terms of the forms of their transactions with their explicit or implicit victims.
- Consistency: Offenders have been shown to exhibit similar patterns of action on different occasions. The most reliable examples of this currently are in studies of the spatial behavior of criminals.
- Inference: Under limited conditions, it is possible to show associations between the characteristics of offenders and the thematic focus of their crimes.
In general, these results provide support for models of thematic consistency that link the dominant themes in an offender’s crimes to characteristic aspects of his or her lifestyle and offending history.
We never analyze anything in isolation but compare new information to the existing knowledge about similar past and parallel events. Both psychological evaluations and crime investigations follow this pattern of determining what a criminal is and what a crime is. That is what the radex model addresses.
In your main post:
- Analyze the different components of the radex model of criminal differentiation, looking at expressive and instrumental criminal conduct against person and property on a continuum of increasing seriousness.
- Include in your analysis a summary of the domains and a critique of how they can be or cannot be useful for forensic psychology and for criminal justice professionals. What are the limitations you see in relying on this approach?