"Psychological Crime Scene Tape: The Investigative Use of Rapist Motivational Typologies," presented on February 19th, 1999 at the American Academy of Forensic Sciences Annual Meeting in Orlando, Florida


Brent E. Turvey, M.S.
Knowledge Solutions LLC
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San Leandro, CA 94577


Learning Objectives: This presentation has three primary objectives. Firstly, to discuss the current use of the Groth rapist motivational typologies as adapted in the published literature by Robert Hazelwood and the National Center for the Analysis of Violent Crime (NCAVC). Secondly, to demonstrate that rapist motivational typologies classify offender behavior, and not offenders, by presenting a case which illustrates this point. A single rapist evidences motivational behavior from two separate typologies within a single attack. The final objective of this presentation is to explain, and inform a discussion on, the investigative consequences of the inappropriate use of the rapist typologies in unsolved cases.

In 1979, A. Nicholas Groth, an American clinical psychologist working with both victims and offender populations, published a study of over 500 rapists. In his study, he found that rape, like other crimes that satisfy emotional needs, is complex and multi-determined. That is to say, that the act of rape itself serves a number of psychological needs and purposes (motives) for the offender. The purpose of his work was clinical, to understand the motivations of rapists for the purpose of the development of effective treatment plans.

Law enforcement and those engaged in criminal profiling adopted the Groth typology and began to use it investigatively. Ultimately the Groth typology was taken and modified by the FBI's NCAVC, and used as part of the basis for the Crime Classification Manual, a project designed to create a DSM type reference specifically for criminals.

From Groth's studies, and the work of others such as those affiliated with the NCAVC, a rapist motivational typology has been developed that most often places offender behavior into one of five typologies:

All too often, investigators and profilers use motivational typologies and other sorts of offender classifications to label a rapist's behavior with a single investigative "diagnosis." The characteristics associated with whatever typology appears to match the rapist best are often issued to investigators as a misguided boilerplate replacement for a thoroughly rendered criminal profile. This results in misleading investigative generalizations, and inappropriately pigeonholes an unknown rapist into an inflexible classification. The typology becomes the equivalent of psychological crime scene tape; a barrier which investigators all too often fail to look beyond in the search for evidence.

The current typology does not provide a dynamic, developmental scale that measures a rapist over time. It is an assessment of rapist behavior at a particular moment, in a particular setting, with a particular victim. The typologies are not to be confused with full criminal profiles, nor by any means should they be considered an exclusive list of potential signature aspects (motivational themes for behavior patterns). They provide a psychological snapshot of a rapist during a single instance from which some reliable inferences about motive can be made. There is also no bright yellow line between the typologies, meaning that a single rapist can evidence behaviors suggestive of more than one motivation. The typologies should be used to help understand the needs satisfied by offender behavioral patterns at one point in time, rather than forcing the offenders themselves into inflexible classifications.

Case: An offender abducts a victim from her broken down vehicle. He tortures her in a van, parked a few blocks away, with a pair of pliers and yells at her to scream so that he can hear it. Between attacks on this same victim within the space of a few hours, he engages in caressing and fondling behavior while apologizing. He finally releases her, after helping her put her clothes back on. The evidence of torture suggests a sadistic signature aspect, while the caressing, fondling, and apologizing suggest a reassurance oriented signature aspect.

Human behavior and human needs are developmental in nature, not fixed and static. Rape is a behavior that is expressive of multi-determined needs. Using the motivational typologies to "diagnose" a rapist as a certain type can have limiting effects on an investigation, not unlike improperly placed crime scene tape. It can result in ignoring other offender motivational patterns, incorrect investigative assumptions, and ultimately overlooked physical and behavioral evidence. All of this working together facilitates the inability of investigators to link and investigate related cases. To avoid this pitfall, the motivational typologies should be used investigatively to suggest the motivations of an offender that are apparent in the given patterns of crime scene behavior, not as rigid diagnostic classifications.

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