Crime Scene Reconstruction

Crime reconstruction (aka crime scene reconstruction) is a fairly new area of study that became popular in the 1990s which many people loosely associate with profiling, psychological autopsy, or equivocal death analysis. Certainly, there are similarities between the four methods, but there are important differences. Profiling, for example, has its origins in the 1974 creation of the FBI's Behavioral Science Unit. Linkage analysis or signature analysis are subfields of profiling that have the closest ties to crime reconstruction. Psychological autopsy is a term first coined in 1977 by the Los Angeles Medical Examiner's Office to investigate suicide cases (Shneidman 1977). Equivocal death analysis (EDA), sometimes called equivocal death evaluation, is a term that first appeared during the 1989 USS Iowa incident in which Clayton Hartwig presumably blew himself up. Something is "equivocal" (as opposed to unequivocal, or certain) when conclusions lend themselves to different interpretations. Usually, the mode of death is equivocal (Ebert 1987), but Annon (1995) states it is when the manner of death is open to question.

Reconstruction involves the use of scientific method, logical reasoning, sources of information on people, criminology, victimology, and experience or skill to interpret the events that surround the commission of a crime. Bevel & Gardner (2001) define it as determining the most probable sequence of events. Reconstruction begins when detectives conduct a walk-through of a crime scene, simulating the events that may have happened in their minds. They sometimes call it getting a "feel" for the crime scene, but the process is as much cognitive as emotional. They are attempting to prove and disprove any sequence of events that may have happened. Some argue it has been a part of detective work for a long time (O'Hara & O'Hara 1973) and is what Osterburg & Ward (2000) call reconstructing the past. Although crime scene reconstruction involves walking through a crime scene, it should not be confused with crime scene analysis (or investigation) which is a standard part of police work. We are concerned here with forensic science, not investigative science.

Reconstruction is frequently done by senior criminalists, senior detectives, retired investigators, and a loose conglomeration of consultants from fields as diverse as anthropology (Mannheim 1999), sociology (Sanders 1974), history (Winks 1969), religion (Woodward 1990), and engineering (Carper 2001). Most consultants (including profilers) can be best utilized by visiting the crime scene while fresh, but they can sometimes work with information and documentation afterwards involving the physical evidence, witness statements, and the reports of other experts. Information such as the angles of shots, length and width of bloodstains, and wound patterns are highly important to most experts.

It is important to note that reconstruction is NOT the same as re-creating the crime scene or re-enacting the crime scene. Crime reenactment has nothing to do with criminalistics or scientific principles. Reenactment is typically seen in courtrooms when defense lawyers stage a jury show or present some sort of computer-animated virtual reality presentation to bolster their version of what they say happened. The rules of forensic law are quite strict on such demonstrations, and in fact, the rules for demonstrative evidence are deserving of some extended discussion, as follows:

THE RULES ON DEMONSTRATIVE EVIDENCE

The days are gone when courts took juries on expensive field trips to the crime scene. Just about anything they need to see can be accomplished with the use of exhibits, models, reconstructions, videotapes, and animations. Almost anything "visual" ("sound" still enjoys certain Fifth Amendment protections) can be presented in modern courts (under certain rules) and the effects are dramatic since people retain 87% of what they see and only 10% of what they hear. Visual exhibits generally fall into one of two (2) categories: (1) real evidence; or (2) demonstrative evidence. So-called "real" evidence is evidence that, in a sense, speaks for itself, as when the prosecutor holds up a bag containing the murder weapon, asks the police officer "Is this the weapon you found?" and then enters it as "Exhibit A." Even though it is authenticated by a witness, real evidence is separate, distinct, and doesn't rely upon a witness' testimony. It has the weight of being additional evidence and can serve many purposes.
Demonstrative evidence is evidence that illustrates or helps explain oral testimony, or recreates a tangible thing, occurrence, event, or experiment. Scientific evidence falls into this category, as when a toxicologist testifies that the victim died of lead poisoning and refers to a chart of the human body showing the circulatory pathways that the toxin traveled. Visual aids of this type are intimately tied to the credibility of the witness who testified with them, and although they are not separate pieces of evidence, like real evidence, a jury can usually view them again while it deliberates. Here's a list of some (not all) of the things that can be used as demonstrative evidence:

plaster casts or molds
scale models
maps, charts, diagrams, and drawings
police composites, mug shots, sketches
photographs
microscopic enlargements
videotapes
computer reconstruction or animation
scientific tests or experiments

(1) The most general rule is that there must be some other piece of evidence -- a fact, an object, or testimony -- that needs to be illustrated or demonstrated. Presentation is actually a two-stage process: first some issue of fact, then the explanation or demonstration stage. Demonstrative evidence is intended to be an adjunct to testimony.
(2) The next most general rule involves the foundational requirements for demonstrative evidence. Certain preliminary steps must be followed such as authentication and accuracy. This is known as "laying the foundation" and is mandatory whenever any scientific expertise is about to be forthcoming. Foundational requirements (other than those dealing with the expertise of the person) usually involve:

authentication -- the demonstrative evidence should convey what it is meant to convey. What it conveys must not alter, distort, or change the appearance or condition of something in any significant way. A computer enhanced photograph, for example, to make a crime scene area look lighter than it actually was is probably inadmissible. There are specific rules, however, that do allow computer enhancements under some circumstances.
representational accuracy -- the demonstrative evidence should fairly depict the scale, dimensions, and contours of the underlying evidence. A photograph or chart with some small section of it enlarged to focus in on is probably inadmissible. This is followed rigorously whenever comparisons (such as between two samples of handwriting) are made so that any lay person can compare the evidence oculis subjecta fidelibus.
identification -- the demonstrative evidence must be an exact match to the underlying evidence or the testimony illustrated. This requirement is the same as with real evidence. For example, an expert witness is about to testify using a enlarged photograph (to scale) clearly showing the outline of a bootprint with a unique manufacturer mark on the bottom of it. The victim (or police officer if the victim didn't survive) who was boot-stomped by it must identify that mark as the one that boot-stomped her. It's often said that demonstrative evidence inherently favors the prosecution, and for two reasons. One, there's usually NO stipulation allowed. A stipulation is when either side gives up on some issue at some point in trial and says "We'll stipulate that our client owns a boot with that particular mark, your Honor" for example. Instead, the defense, who might want to move the trial along has to suffer through a long, drawn-out, embarrassing, and potentially damaging situation. Two, usually along with the process of laying the foundation for demonstrative evidence, the jury also gets to look at what is being authenticated, represented, or identified. If an objection to the foundation (or later challenge for prejudice) is successful, the exhibit is taken down, but the impression remains on the minds of the jurors, even if the judge instructs the jury to disregard it. This is called jury view, and some attorneys consider it to have certain tactical advantages. It's also one of the reasons why pretrial Frye or Daubert hearings are so important.

(3) The next most general rule is that demonstrative evidence must pass the "three hurdles" of admissibility: relevancy; materiality; and competency. Despite some disagreements over the precise meaning of these terms, relevancy means the demonstrative evidence has something to do with the reason the trial is being held, a point at law, a question of guilt or innocence, etc. Materiality means it goes directly to the purpose of illustration, is easily understandable, produces no wayward inferences, and is not just an exercise in "educating" the court or jury. Competency means it's the kind of thing that fits with the decor and decorum of the court, is on the up-and-up, ethical, and doesn't taint the court or subvert the justice process.
(4) The last most general rule is that demonstrative evidence must pass an additional balancing test for relevancy -- a weighing of what is probative/prejudicial. Probative is what is relevant to "cinch" the case for the prosecution by anticipating all defenses. Prejudicial is whatever inflames the passions and prejudices of the jury. This rule necessarily favors the defendant, in rooted in the principle of fundamental fairness, and protects them from unwarranted inferences about bad character or habit. It's important to understand that the weighing of what probative/prejudicial varies with each and every case, and is not an arbitrary standard. It should NOT be referred to as the "gruesomeness" standard, as it sometimes is called. The mere fact that a photograph, for example, shows a shocking crime scene does not automatically make it gruesome or inflammatory. The courts have also ruled that a photo of a nude, bloodstained body is not inadmissible, but innocuous. Autopsy photos are another matter, and depend upon how much cutting and opening the forensic physician has made. In each case, the intent, principal value or effect of the evidence is to be judged as prejudicial, not so much the evidence itself. An extension of this makes it prejudicial error to dwell unnecessarily long on such evidence.

    There are more guidelines for specific kinds of evidence, involving established practices or procedures for the presentation of various types of demonstrative evidence. In this respect, practices may vary considerably by jurisdiction, but in general, here are some of the specifics:
    (1) Plaster casts, molds, and models -- these are most admissible when viewable in all dimensions. Three-dimensional is always better than two-dimensional. Whatever construction material is used doesn't matter. Models of the crime scene are a regular feature of trials, and models that are not precisely to scale will also sometimes be admitted if they are professionally made and presented. An attorney, for example, cannot take a Styrofoam head and stab a knife through it in order to demonstrate the attack on the victim. Further, no one is usually allowed to play around with the models, and this is what was mostly involved in the controversy over anatomically correct dolls in the late 1980s.
    (2) Maps, diagrams, sketches, and charts -- it's generally not important that the original creator of a map testify, only that whatever used is "official." Police-generated sketches and diagrams fall generally within judicial discretion where accuracy is the main concern. Sometimes, the evidence is taken as hearsay, or falls under one or more hearsay exemptions. A lot depends on the conditions of fairness and reliability at the time the sketch or diagram was made. Charts are viewed as useful adjuncts to testimony or not.
    (3) Photographs -- the broad use of photographs is permitted. The photo must substantially and accurately depict the subject matter, and not be unduly prejudicial. Photos that support only one party's theory, or a small part of a theory, are considered self-serving and untrustworthy. Examples of such inadmissible evidence would be staged or posed photos. Some courts place limits on lens, filters, color, and other special equipment, but not many.
    (4) Enlargements -- some courts place limits on the magnification allowed, no more than twenty power, for example. Photographs taken through microscopes depend upon the standardized criminalistics of the crime lab for a state or region.
    (5) Videotapes -- videotaped depositions and confessions are becoming common, and in civil cases, the practice of a "day-in-the-life" video is often admitted. The practice of taping drunk drivers is also popular in some states, but is best considered as real, rather than demonstrative, evidence. Courts have upheld surveillance imagery of the perpetrator in action at the scene of the crime. With demonstrative evidence involving motion, each "frame" or specified number of milliseconds is considered a separate piece of evidence. In other words, a movie is treated as a series of still photographs since the courts are more comfortable and familiar with still photography. Any audio portion of a videotape cannot be played (due to 5th Amendment concerns), or if it is, requires separate authentication.
    (6) Computer reconstruction -- reconstructionists are a fast-growing forensic specialty, and the expertise involves a projection of possible outcomes mathematically predicted by a computer program. For example, known facts such as weight, physical dimensions, and surface friction are plugged into a computer algorithm to generate an accident simulation. It must be shown the simulation (algorithm) is based on accepted principles of physics, and there are sometimes further requirements involving the credentials of the expert.
    (7) Scientific tests/demonstrations -- if a laboratory test is performed in front of the judge and jury, the benefit is that jurors would be allowed to draw independent inferences from it rather than being warned by the judge later that they are free to disregard the scientific testimony. The standard, therefore, is substantial similarity. The expert presenting a test, upon being qualified, is assumed to represent the theory of virtual certainty that the test would yield consistent results if replicated under substantially similar conditions. However, cross-examination of such experts is notoriously fierce.

Many instructors, myself included, hesitate to expose students to the checklist approach with something as important as criminal investigation. The problem is there will always be someone who follows the checklist so closely they never learn anything, but are capable of going thru the motions. Crime reconstruction is so situation- and logic-dependent that it defies standardization. With that being said, and with full awareness that checklists can be easily found elsewhere and are frequently used by rookies, here's some basic protocols that might be followed in the process.

The most basic steps are outlined by Turvey (1999), and consist of the following: (1) WOUND PATTERN ANALYSIS, (2) VICTIM STATE OF MIND, and (3) VICTIM MENTAL HEATH. One of the things you'll note instantly is a focus on the victim and victimology. Wound patterns should be examined at both the crime scene and at the autopsy, with the basic questions to be asked if the deceased could have caused the injuries or was familiar with methods of death. The investigation should then spend the next 20-30 hours studying police, school, hospital, and employment records, along with interviewing various people about the victim's background. Look for the classic warning signs of suicide, like giving away possessions, or sudden cheerfulness after a bout of depression. If suicide can be ruled out, the information you've gathered will help you with the rest of the investigation. Here's how you would investigate the victim as in a psychological autopsy:

    1. Alcohol and drug history, decedent's history of dealing with stress, medical history, family medical history, recent stressors in the victim's life, military history, employment history, educational history, sexual history, dietary history
    2. Interpersonal relationships, writings by the deceased, books and music owned by the deceased, web sites visited, phone calls made, recent conversations with friends, acquaintances, relatives, co-workers, and teachers, interests and hobbies shared with others, old and current enemies
    3. Reactions by any of the above parties to the victim's death, especially as to the degree of lethality, as well as the usual questions about early warning signs and who might have intended harm
    4. Assessment of intention about the role of the decedent in their own demise, including any sub-intentional, covert, or unconscious role, this obtained by analyzing the pattern of how the victim went about accomplishing their goals or life plans
    5. Fantasies, dreams, thoughts, premonitions, fears, or phobias of the victim, socio-emotional mood swings, mental status exam, concentration and judgment abilities, IQ
    6. Timeline of events leading up to the day of the deceased's death

Homicide:	Rape:	Robbery:	Burglary:
1- focus on deceased 2 -crime scene 3 - crime lab	1- focus on victim 2 - medical reports 3 - crime scene 4 - usual suspects	1 - modus operandi 2 - crime scene 3 - police records	1 - focus on scene 2 - records check 3 - property check
*Source: adapted from Gilbert, J. (1980) Criminal Investigation. Columbus: Merrill.*

LEVELS OF CERTAINTY AND LEVELS OF PROOF
PROOF	Intuition	Probable Cause	Preponderance of Evidence	Clear and Convincing	Beyond Reasonable Doubt	Scientific Certainty
EVIDENCE	hunch, guess, or gut feeling	facts a reasonable person would accept	Corroborated facts, eyewitness testimony, physical evidence, or evidence interpreted by an expert			Precise facts with known accuracy
QUANTITY	articulable suspicion about possible facts	prima facie, presumptive but rebuttable facts	Over 50% of facts are in support	Slightly less facts than beyond reasonable doubt	Sufficient facts to preclude every reasonable alternative hypothesis	Overwhelming facts
CERTAINTY	apparent	possible	Basis for hypothesis formulation		Basis for theory construction	Seldom achieved
LAW	suppressed	basis for binding over to next stage	Civil law standard of proof	International law standard of proof	Criminal law standard of proof	Seldom used
INVESTIGATION	useful during early stages	basis for arrest or search warrant	basis for confession and informant law		basis for conviction	Seldom used