8127/frame/fm

 
1.
What Is a Crime Scene?
It is crucial to understand that, like many other aspects of forensic science,
we look to the law for the definition of a crime scene. For practical purposes,
a crime scene is the aftermath of an event that is considered, by law, to be
illegal. Only if good reason exists to suspect that an illegal action has occurred
is law enforcement called to the scene. Before we get too far into any investi-
gation, we must first establish that a crime has, in fact, been committed. Many
interesting events may occur that could make for fascinating analyses, but
unless such an event results from an illegal act, a forensic analysis performs
no useful function. For example, sexual intercourse between two consenting
adults is not a crime; if force is involved, the crime of rape has been committed.
 
Figure 8.2
 
Crime scene pyramid. 
The crime scene is the apex of an inverted
pyramid that expands to encompass the investigation of a crime, the recognition,
analysis, and interpretation of evidence; and finally a court trial. As such, it bears
the full weight of all that is to come. Any mistakes made in processing the crime
scene are impossible to rectify.
Crime Scene
Collection
Interpretation
Court trial
Evidence recognition
In
vestigation
In
vestigation
Analysis
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Principles and Practice of Criminalistics
The question of criminality must always be answered when a dead body
is discovered. Was foul play involved or was it a natural death? We once had
a student ask us if it was necessary to continue with an investigation if a
death appeared to be an “obvious suicide.” We suggested that what appears
“obvious” might not be the truth. Given the number of homicides that are
set up to look like suicides, or even natural deaths, to the casual observer,
it’s clearly important to establish both 
 
what
caused the death and 
 
who
caused
the death.
A woman found her boyfriend lying unconscious and bleeding. She imme-
diately called 911 and an ambulance arrived to whisk him away to the
hospital. Because the man was unconscious when he was found, he couldn’t
say what had happened to him. Two detectives and a criminalist couldn’t
determine from the crime scene alone whether his injuries were self-inflicted
or caused by another person, or whether they were accidental or malicious.
The blood patterns could have resulted from either scenario and no other
evidence presented itself. It was not clear that a crime had, in fact, been
committed until the victim regained consciousness and was able to relate
that he had been attacked.