Criminal profiling depends on a view of human behavior that has been disproven by empirical psychologists, namely that personality dispositions are innate, internal and that they, and not situational factors, most often determine how offenders behave. Those who believe in CP believe that behaviors are consistent across their varying crimes and that their criminal behaviors can be linked to their backgrounds and to various facets of their daily lives.
This means that profilers believe they can correctly link crimes that may or may not be part of a given series to the same offender who will exhibit the same behaviors and that they can predict background characteristics on the basis of types of crime committed. But there is very little evidence that this can be done in any type of crime, and, when some evidence of success is reported in a given study, it has not been replicated by anyone else.
Further, empirical psychologists Snook, Cullen et al. (2008) cited Bateman and Salfati's (2007) study of the consistency of crime scene behaviors among a sample of serial murder cases. They found no evidence that serial killers behaved consistently across their crimes, a finding which throws doubt on the notion that "signatures" can be used to link cases, as the FBI has claimed (see, e.g. Douglas & Olshaker, 1995). Snook, Cullen et al. considered this finding particularly worrisome because profiling is so frequently used in serial murder cases (Snook, Haines, Taylor, & Bennell, 2007; Trager & Brewster, 2001).
And finally, although this author had no particular interest in evaluating profiling, Ritter (1988) addressed three questions in her study that closely follow Snook, Cullen et al's. (2008) discussion of the FBI's characterization of offenses, of offenders and of the correspondence between the two. In Ritter's study, no assumptions were made. Rather, basic questions were asked in each of 27 serial murder cases, and systematic descriptions provided the answers. This is precisely the type of study recommended by Bateman and Salfati (2007), who suggested that future studies of signature use a "more in-depth qualitative empirical evaluation of individual series:"
The questions are: What are the characteristics of serial murderers? What is the nature of the crimes? And, of particular relevance, what, if any, correspondence exists between the offenders and their crimes? The findings indicated that there was no correspondence between the backgrounds of serial killers and the types of crimes they committed, whether viewed individually or as a whole. (When we return to reporting on this study, such findings will be fully elaborated.)
Since there is no scientific evidence for profiling, why is it so widely believed? The next article addresses that issue.