The use of facet action system theory in crime scene analysis and suspect interviewing

Facet action system theory (FAST) is a unified approach able to assist in the investigation of a range of crimes. The theoretical backdrop and methodological foundations of FAST are thoroughly reviewed and studies which have successfully made use of the framework to classify offences and offenders are considered. Particular attention is given to the way in which the model has been applied to organise actions in the domains of homicide, arson and sexual offending by subjecting multifarious crime scene behaviours to types of multidimensional scaling. In addition, the findings of a recent study testing the functional consistency across time and context of FAST within the same individual are discussed. The results indicate that the majority of individuals are true to modal type and suggest that even though the independent behaviours describing a particular mode may change across situation and time, the underlying psychological function of each mode remains the same. Given these findings, a promising avenue for future research lies in the application of the model to inform the interviewing of suspects and in testing for similarities and differences across the various forms of sexual violence.