Global Dynamics

Inteligence Profiling

Define and discuss the meaning of offender "signature" as discussed in the text book reference the offender(s) behaviors.

According to Douglas Et al signature or calling card is “criminal conduct {that} goes beyond the actions necessary to perpetrate the crime. It composes a unique and integral part of the offender’s behavior while is committing the offense.” (Douglas, Burgess, Burgess, & Ressler, 1997, p 261) Signature is something that goes above and beyond those actions necessary to successfully commit the crime. In fact signature increases the likely hood of offender detection due to the fact that it will increase the amount of time that an offender is required to spend with the victim. Also, while MO will evolve from first crime to last crime (as the offender learns what does and does not work) signature for the most part will remain the same but will begin to increase in level of brutality.

Turvey explains signature behavior as “the theme of the crime; they are committed to satisfy psychological and emotional needs.”(Turvey, 2012, p 154)

In both of these cases signature is being defined as what an offender needs to do to make the crime psychologically and/or emotionally satisfying. For example in the case of serial murder and/or rape, the offender has committed the crime repeatedly in fantasy. He had planned every aspect of the crime before ever actually committing the crime. The signature elements of said crime are those things that the offender has done in fantasy such as in cases of rape a script that the victim is required to repeat during the assault or the types of ligature used during a homicide (type of ligature, kinds of knots).

All in all a signature if a specific type of behavior that the offender needs to engage in from crime to crime that will make the crime psychologically satisfying. This will be an offender specific behavior.

Discuss the meaning and significance of case linkage, probative linkage and investigative linkage, reference modus operandi. Provide examples of each and discuss the elements you found interesting and how they apply.

  • Investigative linkage “is a general class connection between one or more cases that serves to inform the allocation of investigative resources”(Turvey, 2012, p 349)
    • An example of investigative linkage would be “finding two women raped in their homes, in generally the same fashion in the same community over the course of a year”( Savino, & Turvey, 2011, Kindle)
  • Probative link “is evidenced by either a unique offender behavior or a unique offender signature that is shared across two or more cases with limited behavioral dissimilarity.(Turvey, 2012, p 349)
    • An example of a probative link would be identification of the offender’s signature behavior with a limited about of behavioral dissimilarity (“behavioral factors have been compared and are dissimilar. Two rapes occur. One involved the use of victim controls with a handgun the other involves victim control by means of manual strangulation.”(Savino, & Turvey, 2011, Kindle)
  • Case Linkage also referred to as “linkage analysis is the process of determine whether distinctive connections exist between two or more previously unrelated cases(Savino, & Turvey, 2011, Kindle)

These three areas are used to investigators to provide a link between cases. These types of linkage will take offender behavior or signature elements into account in an attempt to link a series of cases. It would appear to be most important to begin with case linkage, it is through this type of linkage that a series of cases can be connected to one another and therefore to a single offender instead of investigating each crime as an isolated incident crimes can be investigated as a group or series of crimes which will lead to the second step of linkage or investigative linkage, once crimes are linked to one another investigative linkage can be used to property allocate resources to investigate a series of crimes instead of investigating one incident. Finally a probative link can be used to identify the signature between crimes.

All case linkage elements are important in their own way to offer an overall picture of the offender. It is important to note that no investigation will occur in a vacuum; therefore a criminal profiler will be unable to offer a complete profile without a proper investigation. The above mentioned lineage areas offer methods to combine both behavior and investigative/forensic information to offer a complete profile and/or investigation into criminal activity.


Douglas, J. E., Burgess, A. W., Burgess, A. G., & Ressler, R. K. (1997). Crime classification manual. San Fransisco, Washington, London: Jossey-Bass Publishers.

Savino, J. O., & Turvey, B. E. (2011). Rape investigation handbook (2nd ed.). Waltham, MA: Academic Press. Kindle edition.

Turvey, B. E. (2012). Criminal profiling: an introduction to behavioral evidence analysis (4th ed.). St. Louis: Elsevier. Print