All cases start with the crime scene. This is where bad things happen and mistakes are made that influence the eventual outcome of any case. There is nothing more important in any judicial proceeding and consequently this is our main focus when reviewing or participating in any given scenario. Listed below are the areas in which we pay particularly close attention to:
- Action evidence
- Associative evidence
- Assumption of integrity
- Chain of custody
- Contact evidence
- Crime reconstruction
- Directional evidence
- Evidence dynamics
- Inferred evidence
- Limiting evidence
- Locard’s exchange principle
- Locational/positional evidence
- Ownership evidence
- Psychological evidence
- Secondary transfer
- Sequential evidence
- Temporal evidence
Approaching the Reconstruction
There are several different approaches to the problem of reconstruction. However, the specific approach used by the reconstructionist is not all that must be considered. Ethics, bias, practice standards, the crime scene investigation, chain of custody, evidence dynamics, and many other related issues must be considered. Each shapes and influences the analytical methods used and the behavioral inferences made. The purpose of this page is to introduce the criminal profiler to the problem of crime reconstruction and related considerations, to enable an informed behavioral evidence analysis. Without this foundation, the profiler is guessing, assuming, or otherwise ineptly fabricating the crime-related events that are supposed to be analyzed. Crime reconstruction is based at least in part on a firm understanding of Locard’s exchange principle. As stated by Dr. John Thornton, a practicing criminalist and a former professor of forensic science at the University of California (UC) at Berkeley ( Thornton, 1997, p. 29 ):
“By recognizing, documenting, and examining the nature and extent of evidentiary traces and exchanges in a crime scene, Dr. Locard postulated that criminals could be traced and later associated with particular locations, items of evidence, and persons (i.e., victims). He regarded this postulation as both obvious and ancient, and”
Crime reconstruction is the determination of the actions and events surrounding the commission of a crime. A reconstruction may be accomplished by using the statements of witnesses, the confession of a suspect, the statement of a living victim, or the examination and interpretation of physical evidence. It requires the ability to put together a puzzle using pieces of unknown dimensions without a guiding picture. Like criminal profiling, crime reconstruction is a forensic discipline based on the forensic sciences, the scientific method, analytical logic, and critical thinking. It requires an understanding of Locard’s exchange principle, the ability to recognize and mitigate bias, and the willingness to abandon theories once they have been disproved. This remains true regardless of which reconstruction method is used.
Crime reconstruction is a scientific endeavor that is best performed by qualified forensic scientists. Criminal profilers must either have such a background or work closely with those who do. When the criminal profiler is not a practicing forensic scientist, additional education and training in the forensic sciences is necessary to effectively perform BEA-style profiles.
The failure to consider offender actions, victim actions, and evidence dynamics as a part of any crime reconstruction process has the potential to provide for misinterpretations of physical evidence and inaccurate or incomplete interpretations. Any subsequent use of the reconstruction would have a diminished foundation and relevance, compounding the harm in legal, investigative, and research venues. It is the responsibility of forensic scientists to perform reconstructions of the circumstances and behaviors involved in a crime with diligence and to be aware these influences so that their interpretations reflect the most informed and accurate rendering of the evidence.
Crime Reconstruction and Experience
The most common method of crime reconstruction is to base interpretations on experience. Dr. Hans Gross (1924)emphasized the importance of learning from experience in the late nineteenth-century. He wrote that the scientificinvestigator must take pains to learn from everything he observes, not only in his work but also in his daily life. Andquestion everything; question why something has happened, or what has caused it to happen—then investigate.
The reconstructionist, Gross posited, must learn to see effects from causes and then reverse the process and establish causes from the effects. When similar events occur at a later time, the reconstructionist should then be able to extrapolate what he has learned about effects and infer the potential causes responsible. The learning and the discipline urged by Gross should make it clear that he was not advocating the value of raw and uneducated experience but, rather, experience tempered with extensive learning and what he referred to as an “encyclopaedic knowledge.”
As this suggests, experience is not unimportant, but it can lead the naïve, ignorant, or inept reconstructionist astray when applied in isolation. Regardless of the quality of our experiences, and our capacity to learn from them, the experiences we have in everyday life prepare us to make inferences about the possible causes of the effects we see only when we seek to learn from them. Consequently, the use of one’s experience as a knowledge base for developing reconstruction hypotheses and theories, or for inferring the cause from an examination of the effects, is commonplace. It is important to bear in mind that not all experience is equal, not all experience is sufficiently instructive, and not everyone actually learns from his or her experiences. For these same reasons, it also unacceptable to argue “in my experience” as a sole premise to explain how and why an event must have occurred.
Any inference regarding an event must be supported by factual details submitted to thoughtful analysis and rigorous logic. The thoughtful reconstructionist will also prepare citations from the published literature in support of the interpretations when necessary, as he or she may be asked to provide the basis for their knowledge in court. The purely “experience-based reconstructionist” may give examples of his conclusions to demonstrate how he reconstructs but often will not be able to show the logic and science behind his methods. He will also be unable to cite the literature in support of his findings. The absence of such “long division” in his work is in effect an absence of science.