3.3 Crime Evaluation: Signature

The offender signature refers to aspects of the offense that go beyond what is necessary to commit a crime and which are related to an offender's personality. It is what the offender does to realize himself. Signature encompasses the choices an offender makes and the acts  he performs and that establish the them of the crime. These acts are committed to satisfy psychological and emotional needs. Signature behaviors are important as they help investigators, not only to link cases, but also to reconstruct the criminal scenario (see next post), as the offender acts on the fantasy and the scenario that goes with it.

This concept, unlike the MO, is mostly considered being an intangible concept, but reveal the direction of the killer's singular fantasy. This fantasy gives a sense and purpose to his life. There is no specific rule, and usually does not change from one murder to the other in the same series.  This is a reason why signature is important as it is one if not the main element that enables investigators to link different crimes to the same perpetrator. But, similar to MO behavior, it is possible to notice a certain devolution in signature behaviors in some rare cases. This devolution is mostly due to a significant deterioration in the offender's mental state, an increased use of drugs/alcohol, or an offender's growing confidence in his ability between personality, psychopathy, and sexual fantasy (as is the case for sadistic psychopaths). In that case, the offender's fantasy may become confused and/or chaotic possibly because of the over refinement of his fantasy or his over use of the fantasy as a means to escape reality.

Attributing psychological motives to crime scene behavior is complicated by the fact that, unlike aspects of the personality, mental state is not static across time. Therefore, in some situations, signature behaviors would be more a reflection of an offender's psychological and mental state at the time of the offense rather than of an underlying personality structure or of enduring psychopathology. But mostly, signature behavior captures the distinctiveness of a particular offender's needs and can thus best be conceptualized as a reflection of the underlying personality, lifestyle, and developmental experiences of an offender.We all develop representations or templates in our mind and brain depicting the idealized lover and the idealized program of sexual and erotic activity that we project as an image or actually engage in. Criminal behaviors result when the human developmental process is derailed and a person is able to make pleasurable associations with violent or otherwise criminal activities. As an offender's fantasy behavior develops over time, so does the need to live out those fantasies. When acted out, the act itself fuels the fantasy in the mind of the offender and causes it to evolve.

The signature mirrors the offender's core fantasy. Its content demonstrates that perpetrators of sexual crimes fantasize both about general sexual and about offense focused themes.

There are two parts to the signature: the signature aspects (the emotional and psychological themes that the offender satisfies when committing an offense such as profit, anger/retaliation...) and the signature behaviors (acts committed by an offender that are not necessary to commit the crime but that suggest the psychological or emotional needs of that offender).

As much as staging was referring to MO behaviors (see 3.2 Crime Evaluation: MO), posing clearly is part of an offender's signature. Posing occurs when an offender positions the body in a specific way. By doing that he ritualizes the crime scene and expresses, consciously or not, a specific message. The victim then becomes an accessory used to convey his message. 

- This ritualization differs from body degradation that is mostly the result of a lack of control of the offender's anger.

- Posing can encompass the alteration of the body of the victim, a specific way the body is dumped (significant positioning) or the location where the body is dumped (significant street name, landmarks...)

- Posing implies that the offender's fantasy has matured for a long time

- If the posing is controlled, the offender is highly organized, and if the posing is not controlled, the offender is more likely disorganized

- In case of serial killer who poses his victims, it is highly likely that he works alone, without partner