Towards Modern-Day Investigation
Today, criminal investigation is a broad term encompassing a wide range of specialities that aim
to determine how events occurred, and to establish an evidence-based fact pattern to prove the
guilt or innocence of an accused person in a criminal event. In some cases, where a person is
found committing the criminal act and apprehended at the scene, the criminal investigation is not
a complex undertaking. However, in cases where the criminal event is discovered after the fact,
or when the culprit is not readily apparent, the process of criminal investigation becomes more
complex and protracted.
Although in both cases the criminal investigator must follow practices of identifying, collecting,
recording, and preserving evidence; in the case of the unknown suspect, additional thinking skills
of analysis, theory development, and validation of facts must be put to work.
The craft of criminal investigation has been evolving since the birth of modern policing in the
mid-1700s when the Chief Magistrate of Bow Street, Henry Fielding, organized a group of
volunteer plainclothes citizens and tasked them to attend the scenes of criminal events and
investigate crimes. This group became known as the Bow Street Runners. Their existence speaks
to an early recognition that attending a crime scene to gather information was a timely and
effective strategy to discover the truth of what happened (Hitchcock, 2015).
From these early investigators, one of the first significant cases using forensic evidence-based
investigation was recorded. To summarize the account by McCrery (2013) in his book Silent
Witness; in one notable recorded case in 1784, the Bow Street Runners removed a torn piece of
paper wadding from a bullet wound in the head of a murder victim who had been shot at point-
blank range. In this early era of firearms, flintlock muskets and pistols required muzzle loading.
To muzzle load a weapon, gunpowder would be poured down the barrel of the weapon, and then
a piece of “wadding paper” would be tamped into place on top of the gunpowder using a long
metal rod. The wadding paper used in this loading process was merely a piece of thick dry paper,
usually torn from a larger sheet of paper kept by the shooter to reload again for the next shot. The
musket ball bullet would be pushed down the barrel on top of the wadding paper. When the gun
was fired, the wadding paper would be expelled by the exploding gunpowder, thus pushing the
lead ball-bullet out of the barrel as a deadly projectile. This loading process required the shooter
to be in possession of dry gunpowder, wadding paper, and musket balls to reload and make the
weapon ready to fire. The Bow Street Runners considered this weapon loading practice and
knew their shooter might be in possession of wadding paper. Upon searching their prime suspect,
they did find him in possession of that kind of paper and, in a clever forensic innovation for their
time, they physically matched the torn edges of wadding paper found in the victim’s wound to a
larger sheet of wadding paper found in the pocket of their suspect. From this evidence, the
accused was convicted of murder (McCrery, 2013).
This use of forensic physical matching is an example of circumstantial forensic evidence being
used to link a suspect to an offence. This type of early forensic evidence also illustrates the
beginnings of what exists today as a broad variety of forensic sciences to aid investigators in the
development of evidence. This is also the beginning of forensic evidence being recognized as an
investigative tool. In 1892, not long after the Bow Street Runners investigation, Sir Francis
Galton published his book on the study of fingerprints. In 1900, Galton’s work was used by Sir
William Henry who developed and implemented the Henry System of fingerprint classification,
which is the basis of the fingerprint classifications system still in use today (Henry, 1900).
Only a few years earlier, in 1886, the use of photography for the first Rogues Gallery of criminal
photographs was implemented by the New York City Police Department. This first Rogues
Gallery was an organized collection of photographs of known criminals taken at the time of their
most recent conviction for a crime (Byrnes, 2015). Prior to this organized collection of criminal
photos, facial characteristics on wanted posters had been limited to sketch artists’ renderings.
With the advances evolving in photography, having the ability to preserve an actual picture of
the suspect’s face amounted to a significant leap forward. With this innovation of photography,
the use of mugshots and photographic identification of suspects through facial recognition began
to evolve.
These early forensic innovations in the evolution of criminal investigation (such as physical
matching, fingerprint identification, and facial recognition systems) demonstrate a need for
investigators to develop the knowledge and skills to locate and utilize physical evidence that
enables circumstantial links between people, places, and events to prove the facts of criminal
cases. Physical evidence is the buried treasure for criminal investigators. Physical evidence can
be collected, preserved, analyzed, and used in court to establish a fact. Physical evidence can be
used to connect an accused to their victim or used at a crime scene to establish guilt or
innocence. Forensic evidence may prove a point in fact that confirms or contradicts the alibi of
an accused, or one that corroborates or contradicts the testimony of a witness.
Another significant development in forensic evidence from the 1800s started with the work of
French criminal investigator Alphonse Bertillon who developed the Bertillon system of
recording measurements of physical evidence (Petherick, 2010). One of Bertillon’s students, Dr.
Edmond Locard, a medical doctor during the First World War, went on to further Bertillon’s
work with his own theory that a person always leaves some trace of themselves at a crime scene
and always takes some trace of the crime scene with them when they leave. This theory became
known as “Locard’s Exchange Theory” (Petherick, 2010). To this day, Locard’s theory forms the
foundational concepts of evidence transfer theory.
Today, the ability of forensic experts to identify suspects and to examine physical evidence has
increased exponentially when compared to early policing. Scientific discoveries in a wide range
of disciplines have contributed to the development and evolution of forensic specialities in
physical matching, chemical analysis, fingerprints, barefoot morphology, odontology,
toxicology, ballistics, hair and fibre, biometric analysis, entomology, and, most recently, DNA
analysis.
Many of these forensic science specialties require years of training and practice by the
practitioner to develop the necessary level of expertise whereby the courts will accept the
evidence of comparisons and subsequent expert conclusions. Obviously, it is not possible for a
modern-day investigator to become a proficient practitioner in all of these specialties. However,
the modern-day investigator must strive to be a forensic resource generalist with an
understanding of the tools available and must be specialist in the deployment of those tools to
build the forensic case.
In a criminal investigation, there is often a multitude competing possibilities guiding the theory
development of how a criminal incident occurred with circumstantial links pointing to who
committed the crime. Competing theories and possibilities need to be examined and evaluated
against the existing facts and physical evidence. Ultimately, only strong circumstantial evidence
in the form of physical exhibits, testimony from credible witnesses, or a confession from the
accused may satisfy the court beyond a reasonable doubt. Critically, the quality of an
investigation and the competency of the investigators will be demonstrated through the manner
in which that evidence was located, preserved, analyzed, interpreted, and presented.
In the past, police officers generally took their primary roles as first responders and keepers of
the peace. Criminal investigation was only a limited component of those duties. Now, given the
accessibility to a wide range of effective forensic tools, any police officer, regardless of their
assignment, could find themselves presented with a scenario that requires some degree of
investigative skill. The expectation of police investigators is that they be well-trained with the
knowledge and skills to respond and investigate crime. These skills will include:
• Critical Incident Response
• Interpretation of criminal law and offence recognition
• Crime scene management
• Evidence identification and preservation
• Engaging forensic tools for evidence analysis
• Witness assessment and interviewing
• Suspect questioning and interrogation
• Case preparation and documentation
• Evidence presentation in court
In addition to these task skills of process and practice, investigators must also have strategic
analytical thinking skills for risk assessment and effective incident response. They must have the
ability to apply deductive, inductive, and quantitative reasoning to examine evidence and form
reasonable grounds to identify and arrest suspects.
Engaging these higher-level thinking skills is the measure of expertise and professionalism for
investigators. As our current justice system continues to change and evolve, it relies more and
more on information technology and forensic science. With this evolution, the need for
investigators to demonstrate higher levels of expertise will continue to grow.
Topic 4: The Path to Becoming an Investigator
For many people, their idea of what an investigator does is based on what they see, hear, and
read in the media, movies, TV, and books. These depictions characterize personas ranging from
dysfunctional violent rebels fighting for justice by their own rules, to by-the-book forensic
investigators who get the job done clinically using advanced science and technology. The truth
is, good investigation and real-life investigators are unlikely to make a captivating fictional
script. Professional investigators and competent investigation is about the tedious processes of
fact-finding and sorting through evidence and information. It is about eliminating possibilities,
validating events, and recording evidence, all the while engaging in an intentional process of
thinking, analyzing, and strategically working towards predetermined goals; not to mention
extensive note taking and report writing.
Sometimes, new police investigators are, at first, deluded by fictional representations, only to
find out, by experience, that the real job, although having moments of action, satisfaction, and
excitement, is more about hard work and deliberate attention to detail.
Another common misnomer about the job is the conception that investigation is the exclusive
domain of a police officer. Although this may have been true in the earlier evolution of the
investigative craft, it has become much less the case today. This change is a result of the
enactment of many regulatory compliance statutes that require investigative knowledge, skills,
and thinking. Compliance investigators maintain adherence to regulated activities which often
involve legal compliance for industries where non-compliance can pose significant risks that
threaten the lives and safety of people or the environment. These regulated activities are often
responsibilities of the highest order. What starts as a regulatory violation can escalate into
criminal conduct. The investigative skills of compliance investigators and inspectors must be
capable of meeting the same tests of competency as the police.
Not just anyone can become an investigator. There are certain personal traits that tend to be
found in good investigators. Among these traits are:
• Being passionate about following the facts to discover the truth, with a goal of contributing
to the process of justice
• Being detail-oriented and observant of the facts and the timelines of events
• Being a flexible thinker, avoiding tunnel vision, and being capable of concurrently
examining alternate theories while objectively using evidence as the measure to
confirm or disconfirm validity of theories
• Being patient and capable of maintaining a long-term commitment to reaching a conclusion
• Being tenacious and not allowing setbacks and false leads to deter continued efforts
• Being knowledgeable and skilled at the tasks, process, and procedure while respecting legal
authorities and the limitations to take action
• Being self-aware of bias and intuitive responses, and seeking evidence to support gut-
feelings
• Being trained in the processes of critical thinking that provide reliable analysis of evidence
that can later be described and articulated in reports and court testimony
Considering this list of traits, we can appreciate that good investigators are people with particular
attitudes, aptitudes, and intentional thinking processes. These traits all form part of the
investigative mindset. Although you cannot teach someone to be passionate about discovering
the truth, anyone who has these traits can work towards developing and refining their other traits
and skills to become an investigator. Developing the mindset is a learning journey, and the first
step of this journey is to become intentionally aware of and engaged in your own thinking
processes.
Toward this point, the investigator must always be mindful of the proposition of Shah and
Oppenheimer (2008) in their book Heuristics Made Easy – An Effort Reduction Framework.
Shah and Opprenheimer remind us that people have learned to become quick thinkers using
mental short cuts, known as heuristics, in an effort to make decisions quickly and problem solve
the challenges we encounter. They offer the proposition that heuristics reduce work in decision-
making by giving the user the ability to scrutinize a few signals and/or alternative choices in
decision-making, thus diminishing the work of retrieving and storing information in memory.
This streamlines the decision-making process by reducing the amount of integrated information
necessary in making the choice or passing judgment (Shah, 2008).
In this book, we will point out that these heuristic shortcuts are often instinctive or intuitive
reactions, as opposed to well-reasoned, evidence-based responses. Although they may serve us
well in our everyday thinking, they must be monitored and recognized for their short-falls when
we are required to investigate matters where the outcomes are critical.
To achieve the investigative mindset and be an objective investigator, it is important to be aware
of the heuristic shortcuts and other negative investigative tendencies that can become obstacles
to successful outcomes. For example, a good investigator needs to be focussed on the objective
of solving the case and making an arrest in a timely manner, but becoming too focussed can lead
to “tunnel vision”, which is the single-minded focus on a favorite suspect or theory to the extent
that other suspects or alternate theories are ignored. Moreover, a good investigator needs to take
responsibility and be accountable for the outcomes of the investigation; however, taken to the
extreme, this can lead to an investigator taking complete ownership of the investigation to the
exclusion of allowing the ideas of others to provide guidance and influence. Finally, a good
investigator needs to be careful about how much information is shared with others. However,
excessive secrecy can inhibit information sharing with those who might contribute to the
successful conclusion of the case.
Thinking as an objective investigator, it is often necessary to consider and evaluate several
competing theories or possibilities of how a crime was committed and who the suspect may be.
Often, new investigators, or those uninitiated to the objective mindset, will focus on a favorite
theory of events or a favorite suspect, and rush to be first to reach the conclusion and to make the
arrest. There is a trap in shortcuts and the focused rush to make a fast arrest. In this trap, other
viable suspects and theories are too quickly ignored or discarded. This sometimes leads to
investigations being derailed by “tunnel vision”. Worse yet, tunnel vision can lead to the
misinterpretation of evidence, ultimately leading to charges against an innocent person, while the
guilty remain undiscovered.
To summarize the observations made by Kim Rossmo (2009) in his book on criminal
investigative failures, tunnel vision and lost objectivity have been part of the findings in many
public inquiries. Commissioners at public inquiries have concluded that, at times, investigators
relentlessly pursue a favourite suspect. Sometimes an alternate suspect should have been
apparent, or exculpatory evidence was present that should have caused the investigators to stop
and re-evaluate their favorite suspect, but tunnel vision had set in and the objective investigative
mindset had been lost (Rossmo, 2009).
Similarly and not totally unrelated to tunnel vision, other negative thinking responses also come
into play, and can be observed in the behaviors of case ownership and excessive secrecy. It may
seem that an investigator taking ownership for his or her investigation, and maintaining some
degree of secrecy in the management of case related information, is completely acceptable and
perhaps even desirable. However, as happens with any human behavior, it can negatively
influence the outcome of investigations. Information appropriately shared with the right people
can often reveal connections that contribute to the evidence of a case, and investigators must
remain open to this appropriate sharing. Many negative examples can be found where a police
investigator, or even an investigative team, adopted the attitude that the conduct of an
investigation is their own exclusive domain (Campbell, 1996). With that exclusive ownership, no
one else is entitled or allowed to participate, and relevant information that needs to be shared
with others can be jealously guarded. Opportunities are missed for other investigators to see
details that could connect a similar fact pattern or make the connection to a viable suspect.
Understanding the Investigative Mindset
When we talk about the investigative mindset, in part, we are talking about the self-awareness
and the organizational-awareness to avoid negative outcomes. Once learned and practiced, this
awareness can be a safety net against destructive investigative practices (i.e. tunnel vision, case
ownership, and excessive secrecy). Criminal investigation can require complex thinking where
the investigator must assess and determine the validity of information and evidence to guide the
investigative process. This thinking strives to move from a position of mere suspicion to one of
reasonable grounds for belief to make an arrest and ultimately articulate evidence upon which the
court can make a finding of guilt beyond a reasonable doubt. This is a conscious process of
gathering and recording information, and thinking analytically to form reasonable grounds for
belief supporting defendable actions of arrest and charges. From this conscious process, the
investigator in court can articulate a mental map to describe how they derived their conclusions.
As we proceed towards learning the investigative thinking process, keep in mind that:
• Investigative thinking is disciplined thinking, and investigators must be
consciously aware of and consciously in control of their own thinking
• This is a process of being intentionally engaged at a high level of analytical thinking
• This thinking process is strategically focussed, prioritizing investigative plans and
actions to achieve outcomes
• Developing a mental map, the investigator deliberately selects a path of the investigation
will follow. He or she travels that path with the knowledge that the outcomes of the
investigation will only be accepted by the court if the rationale for the path taken can be
recalled accurately and articulated in detail
