◆ SpookStack

The unsolved homicide presents a major challenge to law enforcement officers. These unsolved cases, which often include a sex-related compo- nent, usually have no apparent motive. The victim has been sexually abused, and the nature of the killing indicates behavior patterns that reflect sexual deviation, specific character traits, and perhaps even psychopa- thology. Also referred to as just mur- ders,’ these murders often include severe beating and multiple stabbing of the victim, body mutilation (such as removal of sexual organs), and sexua- lized positioning of the body after death. The FBI's Behavioral Science Unit (BSU) has been involved since 1972 in assisting city, county, and State law enforcement agencies in their investigations of unsolved mur- ders by preparing profiles of the un- identified offenders, after extensive examination of the crime scene data, victim characteristics, and autopsy re- ports. This profile may include the perpetrator's age, race, Sex, socioeco- nomic and marital status, intellectual and educational level, occupation, life- style characteristics, arrest history, lo- cation of residence in relation to the scene, and certain character traits. The Agents responsible for pre- paring the offender profiles have found it useful to classify the type of crime and the organizational structure of the crime scene. The crime is clas- sified as sex-related, nonsexual, or unknown. Evidence of a sexual com- ponent anywhere within the crime scene justifies the sex-related classifi- cation. The organizational structure of the crime scene is determined by evi- dence of the amount of planning and premeditation by the offender, as well as of the offender's control over the victim. For example, a weapon taken to a crime scene and carried away suggests planning, as contrasted with a weapon used and left at the crime scene, suggesting opportunity and spontaneity. in sex-related crimes, the struc- ture of the crime scene provides in- sight into the offender's patterns of behavior. For example, a well-orga- nized crime scene indicates an of- fender with a conscious plan of action after the murder to avoid detection and apprehension. Currently, the BSU is systematical- ly studying their profiling procedures through scientific and statistical analy- ses. Because of the importance Chapter 3 Classifying Sexual Homicide Crime Scenes Interrater Reliability of correctly classifying the crime and the crime scene, we needed to establish the reproducibility of these classifications. This article reports our investigation of the Agents’ ability to reproduce independently each other's classifications. This ability to replicate decisions is called /nterrater reliability. Study Design Six BSU Special Agents with varying levels of experience in profil- ing participated in the reliability inves- tigation. Data from 64 murder scenes, covering a variety of circumstances both sexual and nonsexual, were Se- lected for the study. For each crime scene selected, one of the participat- ing Agents was theroughly familiar with the case. This Agent presented a short description of the crime scene and showed crime scene photos. The presentation was restricted solely to information immediately available at the crime scene; no infor- mation from laboratory tests or later investigation was divulged. This re- striction allowed the other Agents to focus on immediate data. Other de- tails of the investigation, if discussed. by the presenter, might have influ- enced the Agents in forming their August 1985 109