Signature Killers

Crime Scene Calling Cards

A signature is defined as the name of a person as written by himself or herself: a distinctive mark or characteristic indicating identity. Signatures are not solely the purview of murderers but are also often used by serial rapists and stalkers. The signature provides the offender with a greater sense of power, control, and fantasy fulfillment. Signature killers leave evidence at the scene of the crime that indicates identifying personality traits and behavioral patterns. Most signature killers are serial murderers. Some signature behaviors are postmortem activities, for example, mutilation, dismemberment, and sexual activity with a dead victim; but often, the distinctive pattern occurs prior to or during the actual act of murder. The information derived from such evidence becomes one of the most important aspects in the analysis of a violent crime scene and development of a criminal personality profile of a murderer. As handwriting experts determine personality traits from one's penmanship, so do law enforcement officers, detectives, and criminologists read into these signature elements.

The entire concept of serial murder rests on the premise that individuals are unable to cease their continuous murderous actions because of particular psychological needs and fantasies. The crime scene becomes the arena in which killers can perform, perfect, and relive their fantasies by acting out in ways that are unique to their psychological needs. Thus, crime scene behavior is an absolute, constant reflection of the violent and sadistic desires of each killer. Any brutal and destructive action at the crime scene beyond that which is necessary to complete the act of killing is considered signature behavior. Indeed, there are exceptions. Theodore Kaczynski, the infamous Unabomber, was known to have meticulously carved the initials “FC” into the homemade bombs he mailed or personally delivered to his chosen victims. The “FC” is believed to have stood for “Freedom Club,” which was supposed to represent his raison d'être: He was a socially minded Robin Hood whose time it was to warn society of the pervasive ills of technology. This personalization not only made his bombs unique but also made Kaczynski an anomaly even among serial killers.

Murderers can change their modus operandi (MO) but usually not their signatures. The MO consists of methods and techniques often deemed necessary to complete the criminal act. A change in MO may be the substitution of a weapon, for instance, switching to a knife instead of a blunt instrument. This may be an intentional act to confuse law enforcement, or it may be a simple response to the circumstantial factors of the particular murder; for example, in an unexpected struggle, the murderer attempts to quickly control the victim by reaching for a nearby object such as a rock. [Page 437]Signature behavior remains constant and consistent with each violent act because internal factors and influences, not external circumstances, direct the murderous interaction of the offender. The goal of serial killers is to continue to murder without being caught. If serialists believe that their killing techniques are a liability or are ineffective, they are intelligent and cunning enough to change those methods, but their distinctive behavior tends to remain constant.

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