The Criminal Investigative Method of Policing

Profiling largely relies upon identifying an offender's modus operandi (MO) or learned behaviour. An experienced criminal who builds confidence through ability or contact with the criminal justice system, can vary the MO. Douglas (1995 at p. 10) describes this as being dynamic. An offender's MO may include the ability to leave false clues to conceal the real reasons for a crime. For example, a rape victim's house may be ransacked to give the impression the main reason for the offender being there was robbery. Whilst the MO may alter, the offender's signature is less flexible. A signature is the passion behind the commission of a crime.

For instance, if an offender has needed to dominate or humiliate a victim to achieve a desired response, these emotional drives are the signature of the crime. Applications of profiling in serious sex offences In most jurisdictions, the most common use of profiling is in the investigation of murder and rape cases. For our purposes, we will briefly touch upon some of the indicators profilers would look for in conjunction with an investigation of a serious sex offence. Although the legal definitions of rape vary from jurisdiction to jurisdiction, it basically outlaws forced sexual intercourse.

In most reported cases, the victim is female and the offender male. Douglas (1995 at p. 74) holds the three common motives of rapist are domination, manipulation and control. These motives manifest themselves in fantasies that ultimately reach a stage when the offender feels he must move them into reality. Douglas says offenders often believe they have been subject to domination, manipulation and control in their own lives, and they choose a victim to enable them to rebel against these perceptions. The offender needs to reassert himself in his own mind, and dominate someone else.

Douglas (1995 at p. 34) puts it as "… finally he's now calling the shots". Gerbeth (1993 at p. 7) believes human sexuality is entrenched in a person through conditioning and experience. Both good and bad learned behaviors leave an individual with a sensation of what is what is exciting and sufficiently personally fulfilling. Aberrant erotic development during this process leads some individuals to believe they cannot be satisfied within the parameters of 'normal' relationships. The deviation leads to the commission of offences to redress these feelings of inadequacy. Gerbeth's (1993 at p.

7) criteria for the development of sexual deviancy is an anti sexual upbringing, sexual abuse of the child between ages 5 and 8 by the primary care-giver, over exposure to sexually stimulating behaviour and inappropriate and pathological family dynamics. These act as triggers for deviancy in later life. Profilers attempt to predict the criminal personality through awareness of these triggers. As with Brussel's initial profile where certain presumptions were made about attributes of social and ethnic groups, the trap of assigning characteristics to individuals because of the groups they are assigned to be well recognized.

By locking on to stereotypical assumptions , an investigator may lock out evidence that serves to exonerate a suspect. The use of criminal profiling as an aid to investigations may very well be a double-edged sword. As Professor Wilson has indicated, any method of attempting to predict or account for the behaviour of an individual based on assumptions and presumptions of known behaviour is inherently fraught with danger. There are several well-known cases in Australian criminal history where investigators have focussed too closely on assumptions about an unknown offender, only to ignore evidence that ultimately pointed to the real culprit.

The most recent was the so-called 'Granny Killer' case in 1991. Police ignored sightings of a middle-aged well-dressed male (later identified as John Glover, and charged with eight murders) because he did not fit the preconceptions of the criminal profile prepared by psychiatrist Dr Rod Milton (Sharpe, A. 1994 at p. 411). The temptation to believe that profiling allows quick and neat conclusions in often distasteful and frightening crimes must not be allowed to assume prominence over the fact that the psychology of individuals remain largely a mystery to us all.


Boon, J.and Davies, G (1993) Criminal Profiling in Policing Journal Issue 218 Casey, C (1995) The Signature Aspect in Criminal Investigations in Criminal Personality Profiling November Douglas, J. and Olshaker, M (1995) Mindhunter: Inside the FBI Serial Crime Unit Pocket Star Books , New York Douglas, J (1986) Criminal Profiling: A Viable Investigative Tool Against Violent Crime in FBI Law Enforcement December Bulletin Gerbeth, V. (1993) Practical Homicide Investigation 2nd Edition, CRC Press Boston Ressler, R. , Douglas, J. , Burgess, A. , and Hartman C. (1986) Criminal Profiling from Crime Scene Analysis in Behavioral Sciences and the Law Issue 401