FBI method of profiling

In the FBI offender profiling is conceptualised as “a technique for identifying the major personality and behavioural characteristics of an individual based upon an analysis of the crimes he or she has committed” (Douglas, Ressler, Burgess & Hartman, 1986). Amongst profiling methods the approach used by the FBI is most common and has been adopted by profilers in the United Kingdom, the Netherlands, and other European countries (Turvey, 1999). The process this approach uses to determine offender characteristics involves, first, an assimilation phase where all information available in regard to the crime scene, victim, and witnesses is examined (Jackson & Beckerian, 1997). This may include photographs of the crime scene, autopsy reports, victim profiles, police reports, and witness statements. The next phase, the "classification stage", involves integrating the information collected into a framework which essentially classifies the murderer as "organised" or "disorganised". Organised murderers are thought to plan their crimes, display control over the victim, leave little forensic evidence or clues, and often engage in sexual acts with the victim before the murder (Douglas et al., 1986; Jackson et al., 1997). In contrast, the disorganised offender is described as impulsive, such that his/her murders are opportunistic and crime scenes suggest frenzied, haphazard behaviour (Woodworth & Porter, 2002).

Following the classification stage profilers attempt to reconstruct the behavioural sequence of the crime, in particular, attempting to reconstruct the offender's modus operandus or method of committing the crime (Jackson et al., 1997). Profilers also examine closely the offender's “signature” which is identifiable from the crime scene and is more idiosyncratic than the modus operandus (Woodworth et al., 2002). From further consideration of the modus operandus, the offender's signature at the crime scene, and also an inspection for the presence of any staging of the crime, the profiler moves on to generate a profile. This profile may contain detailed information regarding the offender's demographic characteristics, family characteristics, military background, education, personality characteristics, and it may also suggest appropriate interview techniques (Jackson et al., 1997).

Criticism
To profile serial murderers, it is first necessary to link crimes to a type of common offender. To accomplish this, the offender is determined based on classes of action committed at the crime scene. This classification should be reliable and empirically tested in order to assign cases to one group. The classification system should also meet the assumptions of a typology.To specify the characteristics that define a typology which must occur together frequently, and the characteristics specific to one type must not occur frequently with the characteristics specific to another type.

Much criticism surrounding the FBI process of profiling focuses on the validity of the classification stage. In particular, the criticism targets the organised vs. disorganised dichotomy and its theoretical and empirical foundations and assumptions. This dichotomy has become a commonly cited and used classifications of violent, serial offenders (Woodworth & Porter, 2002). The only available study that examines the reliability of the classification system involved the reading of a sexual-homicide case summary. In this study, interrater reliability was found to be between 51.7% and 92.6%. This study, although dated, does provide limited support for the reliability of the FBI sexual-homicide classification system. However, this form of reliability contributes little to the usefulness of the offender profiling system if the classification is not effective. The FBI classification system is derived from a single interview-based research study with a small sample of apprehended serial killers who operated in North America.

The ecological validity of the FBI's classification system considering its limitations has also been criticised. Further limitations of the original study include the subject selection process that relied on non-random self-selection, and the extensive use of potentially biased data. The interviews were unstructured and led in an ad hoc fashion that was dependent on the interviewees. The process whereby participants were divided into groups based on organised or disorganised characteristics and behaviours has been described as the product of circular reasoning, involving the “reification of a concept” in contrast to an empirical validation of this concept.

The organised/disorganised dichotomy is further flawed in that it fails to meet the criteria of a typology. Alexander Canter examined the relationship between the behavioral styles and background characteristics of 100 serial-homicide offenders using a multi-dimensional scaling (MDS) procedure called Smallest Space Analysis (SSA) that statistically represents the co-occurrence of variables. No evidence was found to support the co-occurrence of behavioural styles or background characteristics related to the organised/disorganised taxonomy as proposed in the Crime Classification Manual (CCM).