Crime
Reconstruction
by W. Jerry
Chisum & Brent E.
Turvey
© Elsevier, September 2006
Main | Profiling | Forensic Science | Library | Bookstore | Consultation | New | Contact | Search
|
Crime by W. Jerry
Chisum & Brent E.
Turvey |
Crime Reconstruction
by
W. Jerry Chisum & Brent E. Turvey
Hardcover, 608 pages
Published by Academic
Press, an imprint of Elsevier, 2006
ISBN: 0123693756
PREFACE
A HOLISTIC APPROACH TO
CRIME RECONSTRUCTION
by W. Jerry Chisum and Brent E. Turvey
Relating to or concerned with wholes or with
complete systems rather than with the analysis of, treatment of, or dissection
into parts. Emphasizing the organic or functional relation between parts and the
whole.
—Holistic,
Dictionary Definition
What is the nature of the whole, and what is my nature, and how this is
related to that, and what kind of a part it is of what kind of a whole.
Holistic crime reconstruction
is the development of actions and circumstances based on the system of evidence
discovered and examined in relation to a particular crime. In this philosophy, all elements of evidence that come to light in a given case
are treated as interdependent; the significance of each piece, each action, and
each event falls and rises on the backs of the others. More evidence gives rise
to more meaning, and less evidence necessarily allows for the resolution of less
meaning. The final reconstruction is a function of this system, of
how much evidence there is, and whether and how it interrelates and
maintains its consistency.
A
system of related evidence and any conclusions based thereon are like a
mechanical engine or a biological organ, with few if any extraneous parts
working judiciously, and in harmony, toward a desired end. If one of the parts
fails, then the whole system suffers and may fail. With evidence and its
interpretation it is precisely so. Interpretations must be compatible, working
in concordance to support each other. Or at the very least not working against
each other. Bloodstain pattern interpretations must not contradict the ballistic
analysis, trace evidence must not contradict the conclusions of the arson
investigator, DNA evidence must not contradict the conclusions of the
fingerprint examiner, and so forth. A concordance of the evidence must be
apparent. The reason for this is straightforward. Although it can be forgotten
in a climate that seeks and rewards certain conclusions (namely the climate of
the courts), all science, and even forensic science—especially forensic
science—is grounded in skepticism. It necessarily follows that a finding out
of harmony with any of the others in its system should call one or all into
question.
Origins: The Forensic Generalist
The foundation for holistic crime reconstruction doctrine was introduced
more than a century ago, with the 1894 publication of Handbuch fur
Untersuchungsrichter als System der Kriminalistik (Criminal Investigation: A
Practical Textbook for Magistrates, Police Officers and Lawyers) by the
legendary Austrian jurist Dr. Johann (Hans) Baptist Gustav Gross. The goals of
this manual were formative and ambitious: to establish principles of scientific
investigation and to provide for the birth of the scientific investigator. The
manual was a broad success with international appeal, achieving no less than
five English editions (1906, 1924, 1934, 1949, and 1962). It also provided the
basis for the practical work later undertaken by French scientist Dr. Edmund
Locard when he established what is considered to be the world’s first police
crime laboratory in Lyon, France, in 1910. Despite the passage of time and
advances in technology, the philosophies of System der Kriminalistik remain
a touchstone of forensic knowledge and wisdom to the present day.
The
approach to crime reconstruction advocated by Dr. Gross, and subsequent students
of his work, was to assign such duties to a scientific investigator—what would
be referred to in more modern language as a forensic generalist. The scientific
investigator was to be a professional schooled broadly in the subjects of crime,
criminals, and the scientific methods of their identification, apprehension, and
prosecution. Their role was to understand how the system of evidence and details
of a case could be established, how they could be related, and how they could be
interpreted. This holistic method, branded by dispassion and an adherence to
science, would ideally free the scientific investigator from the constraints of
politics, cronyism, and emotional bias.
The
philosophy of Hans Gross was mirrored in many subsequent published works and
aspired to in numerous crime labs throughout the United States.
The Forensic Generalist Fades
At present, the forensic generalist is all but a memory and until recently
(Turvey, 1999; Inman & Rudin,
2000; Savino & Turvey, 2004)
had not made an honest appearance in forensic science textbooks since DeForest,
Gaensslen, and Lee (1983). More curiously, some forensic professionals
become angered when generalists are described, let alone remembered. There is
more than one reason for the disappearance of the generalist and related
professional sensitivity. We focus on the three most apparent:
overspecialization, diminished crime lab budgets, and the false paradigm of
sides.
The Gross
Facts
Forensic generalists and forensic
specialists alike are a requirement for informed forensic case examination,
laboratory testing, and crime reconstruction to occur. A forensic generalist is
a particular kind of forensic scientist who is broadly educated and trained in a
variety of forensic specialties. They are “big picture” people who can help
reconstruct a crime from work performed with the assistance of other forensic
scientists and then direct investigators to forensic specialists as needed. They
are experts not in all areas, but in the specific area of evidence
interpretation. According to DeForest
et al. (1983, p. 17),
Because of the depth and complexity of criminalistics, the need for specialists is inescapable. There can be serious problems, however, with overspecialization. Persons who have a working knowledge of a broad range of criminalistics problems and techniques are also necessary. These people are called generalists. The value of generalists lies in their ability to look at all of the aspects of a complex case and decide what needs to be done, which specialists should be involved, and in which order to carry out the required examinations.
Specialization
occurs when a forensic scientist has been trained in a specific forensic
subspecialty, such as an area of criminalistics, forensic toxicology, forensic
pathology, or forensic anthropology. Specialists are an important part of
forensic science casework, with an important role to fill. Traditionally, forensic specialists provide the bricks, and
forensic generalists have traditionally provided the blueprints.
In
the modern forensic system, the majority of forensic scientists have become so
specialized in their analytical functions that they are no longer in possession
of the gross facts in the cases they work. This is a source of both angst and
embarrassment to some crime lab personnel, because they would prefer that their
analyses be better informed. Still others would prefer to retain the appearance
of overall forensic authority that knowing the full case facts allows. Nowadays,
a piece of evidence is brought to a crime lab or examiner, it is examined using
a specific method, test, or procedure as the requesting agency dictates, a
report of findings is written, and the overall context may or may not be known
or even sought. Without the gross facts of a case, and at least some knowledge
of assembling them, crime reconstruction cannot occur. Not participating in this
process, for lack of skill, time, or invitation, has become a sore point for
some in the community of forensic science specialists.
Underfunded
and Understaffed
In terms of money, government crime laboratory budgets nationwide rarely allow
for the full suite of forensic specialties, with, for example, trace evidence
units vanishing in the shadow of the forensic titan that DNA has become because
of its acceptance by the courts. Money, after all, is allocated for those areas
of forensic science that the court has embraced. Money is not allocated for
areas of forensic science that the court shows disinterest. Also, money for
research is often a luxury that cannot be afforded at all.
Furthermore,
government labs have faced severe budget and personnel shortages in recent
years. There are several interwoven reasons for this. First, the demand for lab
services has increased with the growing national profile of forensic science
thanks to the popular media. More law enforcement officers are coming to
understand that forensic evidence can help their cases, more juries are
expecting it at trial, and as a result government crime labs are being asked to
do more examinations on more evidence. Second, practice standards in many
regions have evolved to meet the needs of crime lab certification. Nationwide,
many of the larger government crime labs and lab systems are suffering
excruciating independent reviews and scrambling to meet the criteria set by the
American Society of Crime Lab Directors Laboratory Accreditation Board
(ASCLD/LAB) in order to claim this coveted credential in court. To meet
ASCLD/LAB criteria, more of the diminishing lab budget must be spent on quality
control, adequate workspace, and adequate evidence tracking and storage.
Additionally, each person must complete a proficiency test on each type of
evidence he analyzes each year. This slows the amount of time forensic
scientists have to work on case material and can, in extreme cases in which
there are staff shortages, put the examination of evidence on hold for periods
of time. The accreditation process is not easy, and it even requires some labs
to simply start over and build entirely new multimillion-dollar facilities. This
to say nothing of the requirement to hire more adequately qualified personnel,
bringing front and center the problem of too few qualified candidates available
with less money to pay them. Additionally, new forensic analytical techniques
are not encouraged because they must be “proven methods”—refinements of
methods are not allowed. This works against the intention of the scientific
method and stamps out the spark of creativity because many of the past advances
in crime lab analysis were the result of “experimentation” with actual case
materials and trying something new. Third, the public funding of state crime
labs constantly suffers at the hands of wary voters who tend to lack enthusiasm
for raising taxes to help fund education, let alone forensic science.
With all of
these factors at work, many government crime labs do not have the time, the
resources, or the personnel to perform their regular analytical casework. As a
consequence, backlogs have mounted in almost all areas of forensic analysis. In
this environment, the extra time and commitment required for crime
reconstruction is an added expense that becomes difficult for administrators to
justify.
The Paradigm
of Sides
The paradigm of sides challenges forensic
scientists on two fronts, presenting a false choice in which they are invited to
abandon their chosen profession for advocacy. First, there is the obvious
division between the prosecution and the defense. More than a few forensic
scientists work in an environment that rewards them for thinking and behaving as
though there is a morally right side of the courtroom and a morally wrong side
of the courtroom. By choosing fidelity to one side of the courtroom over
another, the forensic scientist not only loses that which defines science,
namely objectivity, but the forensic scientist also presumes a role in court not
meant for any expert or witness - that of the trier of fact. It is not the place
of the forensic scientist to decide who is worthy of a defense, who is legally
or actually guilty, or how they should be punished. These are moral and legal
conclusions, which brings us to the second part of the paradigm of sides: the
division between scientific fact and legal truth. The forensic scientist is an
educator to the court. It is the role of the forensic scientist to establish
scientific fact and explain what it means to an investigator, attorney, judge,
or jury in the context of a given case. Moreover, the scientific facts should be
the same no matter which side the forensic scientist is working for. It is the
role of the judge and jury, not the forensic scientist, to form legal
conclusions about who is guilty of what, and what the penalty should be based on
the totality of evidence.
Although
often confused, scientific fact and legal truth are not the same thing.
Scientific fact is established through careful examination using the scientific
method. Legal truth is determined by the trier of fact, based on available and
admissible evidence, as well as their understanding of the law. This is made
abundantly clear in cases of wrongful conviction, in which a person may be found
legally guilty of a crime without having actually committed it. Juries do not,
consequently, determine the ultimate facts of a case, only the legal facts. This
distinction becomes important when one considers the roles played in our justice
system by directed verdicts, appellate courts, supreme courts, gubernatorial
pardons, and DNA exonerations, all of which have the power to influence or
overturn a juries estimation of the facts and its final verdict. Subsequently,
the abilities of a forensic scientist are not measured in arrests, convictions,
or even acquittals, as will be made evident throughout this work. Forensic
science, although a servant to court, must serve itself first in order to have
any intrinsic value. When science chooses a side other than itself in any
conflict or dispute, it is no longer science but advocacy.
The
majority of forensic scientists have no trouble understanding the gravity
involved in navigating the paradigm of sides on this level and would rather
resign from a case or an agency than sacrifice their objectivity and integrity.
The true forensic scientist knows that his first onus is to his profession, and
that if there is no science, there can be no forensic science.
This
community understanding is all well and good until it is remembered that a fair
number of forensic scientists work in government crime labs that are housed
within, or directly supervised by, police agencies or district attorney’s
offices. In terms of the actual reconstruction of crime, police and prosecutors
are faced with the reality that the scientists they employ may not always agree
with their theories regarding a case. In fact, in some instances, the
evidentiary findings of the crime lab may hamper or even disprove an important
point upon which a police or prosecution theory is built. For some government
agencies, this internal evidence-based self-correction is a welcome adjustment
to the course of a criminal investigation and any future prosecution. However,
history has shown that this is not always so. Not all government crime labs
enjoy an open or healthy relationship with their law enforcement and
prosecutorial supervisors. Also, a significant number of government agencies
remain hesitant to put their scientists in a position in which they can
reconstruct the crime in its entirety and then be called by the defense as
witnesses against them.
The
paradigm of sides presents the forensic scientist with a false choice between
prosecution or defense; between scientific fact or legal truth. Pressure to
choose can be brought to bear in many ways—personal, professional, and
financial. Furthermore, the pressure on a forensic scientist in such
environments, to be part of the “team” and help “get the bad guys,” can
be seductive and overwhelming to the point of assimilation. As discussed later
in this book, the rewards for assimilation are great, and the consequences for
failing to assimilate can be equally great.
Overspecialization,
diminishing budgets, and the paradigm of sides—in such ways the practice and
implementation of crime reconstruction has, with some exceptions, faded from
many crime labs and been moved into the hands of others.
The
authors view this with neither frown nor favor,but rather agree to recognize
that it is so; all manner of reconstruction opinions find their way into court
from a variety of sources. However, in many instances, it has become clear that
scientific reconstructions are being subverted and even intentionally excluded. Consequently, with its departure from the crime lab, the
practice of crime reconstruction is in no small danger of losing its footing on
the ascending ladder that is the employment of scientific principles to evidence
interpretation. Under no circumstance should this situation be acceptable. As
such, the need for the development of this textbook becomes apparent.
Modern Crime Reconstruction
Modern forensic science and crime reconstruction is slowly becoming the work
of police technicians trained inexpensively through short courses and lectures,
as opposed to formally educated forensic scientists shepherded by mentors of
quality experience. The difference between the two is significant. Forensic
scientists do not just test or examine evidence and then record the results;
they are meant to explore, understand, and explain its significance. Thornton
(1997, p. 3) provides a succinct and accurate description:
The
single feature that distinguishes forensic scientists from any other scientist
is the certain expectation that they will appear in court and testify to their
findings and offer an opinion as to the significance of those findings. The
forensic scientist will testify not only to what things are, but to what things
mean.
This is the very heart of crime
reconstruction—not just what, where, and when, but also how and why.
The
reconstruction of a crime from physical evidence is the culmination of a long
and methodical process. It is the last step in the analytical journey each piece
of physical evidence takes from the moment it is recognized at a crime scene.
Those steps occur in roughly the same order for each item of evidence:
1.
Recognition
2.
Preservation
3.
Documentation
4.
Collection
5.
Transportation
6.
Identification/classification
7.
Comparison
8.
Individuation
9.
Interpretation/reconstruction
Traditionally,
the specific duties are broken down as follows:
Detective/investigator/forensic
technician
1.
Recognition
2.
Preservation
Forensic
technician (aka crime scene technician)
3.
Documentation
4.
Collection
5.
Transportation
Forensic
scientist/criminalist
6.
Identification/classification
7.
Comparison
8.
Individuation
9.
Interpretation/reconstruction
The
problem is that these forensic titles and roles are often mixed, misunderstood,
or outright confused, sometimes over many generations of professionals in a
given system. As a result, forensic job titles abound, with more than one to
describe the same set of duties—crime scene investigator, crime scene
technician, forensic investigator, evidence technician, forensic technician,
laboratory technician, laboratory specialist, forensic specialist, forensic
analyst, forensic scientist, criminalist, etc. What is important to remember
about titles is that they are administrative and not necessarily suggestive of a
particular background, education, training, or expertise. It is the work that
defines the professional. It is education, training, experience, and the quality
of work products that define expertise.
For
the purposes of this text, it is important to become disentangled from this
avalanche of jumbled titles and return to classic definitions for the purpose of
clarity.
A
technician is one who is trained in specific procedures, learned by
routine or repetition. A forensic technician is trained in the specific
procedures related to collecting and even testing evidence found at crime
scenes. This is without any need for employing or even understanding the
scientific method and the principles of forensic science. This describes the
police technicians documenting crime scenes and collecting evidence, and more
than a few of the forensic personnel working in government crime labs.
A
scientist is someone who possesses an academic and clinical understanding
of the scientific method and the analytical dexterity to construct experiments
that will generate the empirical reality that science mandates. A forensic
scientist is one who is educated and trained to examine and determine the
meaning of physical evidence in accordance with the established principles of
forensic science, with the expectation of presenting her findings in court. This
describes fewer and fewer of those practicing forensic science in government
crime labs .
As
the authors have experienced on countless cases, it is technicians,
investigators, and ultimately attorneys who are actually providing a majority of
crime reconstructions in court, often with little understanding of forensic
science or the scientific method, to say nothing of the natural limits of
physical evidence. Crime lab personnel are performing any necessary laboratory
analysis, but police and prosecutors are taking the final step to explain events
and their relationships in court. This has the net effect of elevating the lay
testimony of investigators and forensic technicians to that of the forensic
scientist and of reducing the expert findings of the forensic scientist to the
level of the technician.
Without
the proper scientific foundation, technicians and detectives performing crime
reconstructions may do so without a sense of what good science is and what
constitutes the difference between assumptions, opinions, theories, and facts.
To say nothing of failing to understand the actual science beneath the methods
or instruments they employ in the search for evidence, a reality that often
causes their explanations of false positions and false negatives to be works of
useful fiction. In a related fashion, they also tend to fail with regard to
grasping the necessity for testing their theories, and for continually
attempting to falsify them against the revelations of experimentation and newly
developed information. A scientist knows that confirmation of one’s theories
is easy to find, especially if that is all one seeks. Good science is not about
trying to prove one’s theories but, rather, working tirelessly to disprove
them through falsification (Popper,
1963).
Holistic Crime Reconstruction
This
textbook is aptly titled Crime Reconstruction. It is not a manual
intended to explain the technical mechanics of searching or processing crime
scenes or to delineate the rote procedures related to instrumental laboratory
analysis. There are plenty of texts available that adequately cover these very
important considerations, without which reconstruction would be impossible. As
already discussed, holistic
crime reconstruction is the development of actions and circumstances
based on the system of evidence discovered and examined in relation to a
particular crime. It is best conceived as the function of a forensic generalist.
Our purpose is to educate students and prepare
generalist practitioners of the forensic sciences as to the manner in which
interpretations regarding evidence may be legitimately achieved and expressed.
As
we have suggested, not everyone agrees with the forensic generalist model. One
of the philosophical arguments against the generalist is that “one cannot be
an expert in everything.” As already stated, we do not propose that to perform
crime reconstruction one needs to be an expert in all forensic disciplines. We
propose that forensic reconstructionists must become an expert in only one: the
interpretation of the evidence in context. If students wish to pursue
further knowledge about examination and analysis in a particular discipline,
then there are several excellent publications that are available for that
purpose. However, there has never been a textbook devoted only to the
interpretation of evidence in context—the proofs, the perils, and the
prevarications. Consequently, those studying and performing crime reconstruction
have perhaps lacked some advanced measure of informed guidance on the subject.
It is our collective goal to assist with filling that void.
Crime
reconstruction, to be accurate, must be based on a close scientific examination
of the physical evidence and the surrounding environment. These examinations
must be the result of applying the scientific method. Interpretations of the
meaning of subsequent results must be clearly derived by logic and critical
thinking. We will try to explain these concepts so that students can understand
that crime reconstruction is not just mere observation and speculation. We will
also give students several ways to approach the problem of how reconstruction
may be competently performed. Throughout this work we have included
reconstruction techniques, interpretation guidelines, and even practice
standards.
Also,
students will come to appreciate that the crime scene is a dynamic location; it
does not remain virginal or static, as a “frozen moment of time,” but rather
it is constantly subject to change. The greater the time interval between the
crime, the documentation, and examination of the scene, the greater the changes
may be. These changes we have referred to as evidence dynamics. To be
ignorant of the problems inherent in the interpretation of the evidence due to
evidence dynamics can result in serious misinterpretation errors.
Different
areas of physical evidence offer opportunities for reconstruction. Bloodstains,
firearms, arson, and trace evidence all contribute to the whole. We have
included chapters on each of these types of evidence by some of the leading
experts in these fields.
Finally,
there are chapters on ethics and expert testimony so that students may
understand how to comport themselves professionally and what truly waits for
them in the courtroom. The perspectives of the forensic scientist and the
attorney are provided. As readers will come to appreciate, these considerations
are far from trivial.
It
is important for students of forensic science to learn that no one discipline
can truly stand alone in a reconstruction. Each form of evidence must be in
agreement with the other forms that are present. Each part must be meticulously
established and then considered not just on its own but also in its place as
part of the greater whole. What is it, how does it fit, and what does it mean in
context—these are the questions asked by a reconstructionist.
Given this holistic
approach, the authors have come to view reconstruction as the work of one who is
sufficiently educated, trained, and experienced to understand the total body of
forensic evidence and analysis in a case. That is, again, the forensic
generalist. The generalist–reconstructionist, it must be understood, need not
know how to perform all of the forensic examinations that were conducted. They
need not have the ability to operate a camera to view a photograph; they need
not have the ability to extract DNA and amplify it to comprehend a DNA
analyst’s report; they need not have the ability to perform an autopsy to
understand the cause and manner of death, and appreciate the trajectory of the
projectiles that passed through the body. Rather, they must be able to
understand what the results of forensic examinations are, how they were reached,
what they mean, and how they may be integrated to create of picture of events.
Integration of findings is key because crime is best
reconstructed when forged by a collaboration of the forensic evidence, and not a
reliance on one single examination or discipline. To rely on one piece of
evidence, or one theory, without placing it in context is not only potentially
misleading but also a disservice to the justice system that the forensic
scientist ultimately serves. It is our collective hope that this text will be
worthy of that service and will assist the next generation of forensic
generalists with the difficult tasks that are before them.
REFERENCES
DeForest,
P., Gaennslen, R., and Lee, H. (1983). Forensic science: An introduction to
criminalistics. New York: McGraw-Hill.
Gross,
H. (1906). Criminal investigation. Madras, India: Ramasawmy Chetty.
Gross,
H. (1924). Criminal investigation. London: Sweet & Maxwell.
Inman, K., and Rudin,
N. (2000). Principles and practice of criminalistics: The profession of
forensic science. Boca Raton, FL: CRC Press.
Popper, K. (1963). Conjectures
and refutations. London: Routledge &Keagan Paul.
Thornton,
J. (1997). The general assumptions and rationale of forensic identification. In
D. L. Faigman, D. H. Kaye, M. J. Saks, and J. Sanders (Eds.), Modern
scientific evidence: The law and science of expert testimony (Vol. 2). St.
Paul, MN: West.
Savino,
J., and Turvey, B. (2004). Rape investigation handbook. Boston:
Elsevier.
Turvey, B. (1999) Criminal Profiling: An Introduction to Behavioral Evidence Analysis, London: Elsevier Science.
Contact the Authors
Last update: 06/13/2006