2. Agenda for 1 Sept 2010
Roll Call
Pledge (Weather Permitting)
Current Events
Birthday List!!! AM session only
Discussion-JonBenet Ramsey: Who did it?
Lecture: Physical Evidence and the
Crime Scene
Vocabulary/Spelling word of the Day
Reminder: Tomorrow is PANTS day, bring
money if you want to purchase through the
uniform company. ~ $38.00 cash or credit
card. NO checks.
3. JonBenet Ramsey: Who did it?
Discussion: What mistakes were made
during the initial response to the scene
as well as during the subsequent
investigation?
How did these mistakes sabotage any
chances of JonBenet’s killer ever being
brought to justice?
7. Physical Evidence and the
Crime Scene –Chapter 2
As automobiles run on gasoline, crime
laboratories run on PHYSICAL EVIDENCE.
Physical evidence encompasses any and all
objects that can establish that a crime has or
has not been committed or can link a crime
and its victim or its perpetrator.
If physical evidence is to be used effectively,
its presence first must be recognized at the
crime scene.
8. Physical Evidence
Physical evidence achieves its
optimum value in criminal
investigations only when its
collection is performed with a
selectivity governed by the
collector’s thorough knowledge of
the crime laboratory’s techniques,
capabilities, and limitations.
Investigators must use both
knowledge and discretion in
collection of evidence – if every
natural and man-made object
were collected from a scene, the
enormous amount of material
would immobilize a crime
laboratory.
9. Physical Evidence and the
Crime Scene
Thorough and competent
investigations conducted by
professional police officers when
partnered with the crime lab’s
capabilities will enhance the
chances for a successful criminal
investigation.
Forensic science is, and will
continue to be, an important
element of the total investigative
process, but it is only one aspect
of an endeavor that must be a
team effort. The investigator
who believes the crime
laboratory to be a solution for
carelessness or ineptness is in
for a rude awakening.
10. Physical Evidence and the
Crime Scene
Forensic Science begins at the crime
scene. If the investigator cannot
recognize physical evidence or
cannot properly preserve it for
laboratory examination, no amount
of sophisticated laboratory
instrumentation or technical
expertise can salvage the situation.
Not all crime scenes require retrieval
of physical evidence, but once the
commitment is made to process a
crime scene for physical evidence,
certain fundamental practices must
be followed.
11. Preserving and Recording the
Crime Scene
In order to be useful to investigators,
evidence at a crime scene must be
preserved and recorded in its original
condition as much as possible. Failure
to protect a crime scene properly or
record its details accurately may result
in the destruction or alteration of
evidence, or hinder the search for the
perpetrator by misleading investigators
about the facts of the incident.
12. Secure and Isolate the Crime
Scene
The first officer arriving on
the scene of a crime must
preserve and protect the
area as much as possible.
Of course, priority should be
given to obtaining medical
assistance for individuals in
need of it and to arresting
the perpetrator. As soon as
possible, extensive efforts
must be made to exclude all
unauthorized personnel from
the scene. As additional
officers arrive, measures are
immediately taken to isolate
and protect the scene.
13. Secure and Isolate the Crime
Scene
Ropes or barricades along with strategic positioning of
guards will prevent unauthorized access to the area.
Determine the crime scene boundaries. This can be
established after determining the perpetrator’s path of entry
and exit.
The obvious items of crime scene evidence must be
documented and photographed before the initial walk
through.
After the obvious evidence has been documented, then a
walk-through of the scene to gain a better overview of the
situation can be performed. Only KEY personnel should be
included in the walk through.
During the walk through a strategy for systematically
examining and documenting the entire crime scene can be
devoloped, while preserving the integrity of the evidence.
14. Record the Scene
Photograph – The most important
prerequisite for photographing a crime
scene is that it be unaltered.
THE GOLDEN RULE: Do not touch,
move or alter any evidentiary item
until you document the scene!
15. Record the Scene
Photography – Unless injured people are
involved, objects must not be moved until
they have been photographed from all
necessary angles. If objects are removed,
positions changed, or items added*, the
photographs may not be admissible as
evidence at a trial.
* (There will be times when things ARE
added to a scene, for example, things left
behind by the ambulance crew.)
16. Record the Scene
If evidence has been removed or moved before
photographing, the fact should be noted in the
report, but the evidence should NOT be
reintroduced into the scene in order to take
photographs.
A general rule to remember is that you cannot
take too many photographs. Photographs that
are not necessary simply will not be used.
Sometimes certain photographs are taken simply
to jog the investigators memory later when they
are writing their report.
17. Record the Scene
Each crime scene should be photographed
as completely as possible.
Photographs should be taken of the area
immediately surrounding the crime scene and
also of adjacent areas. This is where important
acts occurred immediately before and after the
commission of the crime.
Overview photographs of the entire scene and
points of entry and exit must be taken from
various angles.
If the crime occurred in a house, photographs of
every room must be taken in a similar fashion.
18. Record the Scene
If the crime scene includes a dead body,
photographs must be taken to show it’s position and
location relative to the entire scene.
Close up photographs of injuries and weapons lying
near the body are extremely important. Although
photographs will be taken of the body by the
coroner’s office, it is crucial that photographs be
taken of the injuries while the body is still at the
scene. However, do NOT move the body in order to
take photographs of injuries! The body should not
be moved by ANYBODY except investigators from
the coroner’s office!
19. Record the Scene
After the body is removed from the scene, the
surface underneath the body should be
photographed.
As items of physical evidence are discovered, they
are photographed to show their position and
location relative to the entire scene. After these
overviews are taken, close-ups should be taken
from several distances to record the details of the
object itself.
If the size of an item is significant, such as a
bullet hole, a ruler or other measuring scale may
be inserted near the object and included in the
photograph as a point of reference. Be sure that
the rule that you use can be submitted as
evidence!
20. Record the Scene
Videotaping: The same methods should be used for
videotaping that are used for still photography.
Crime Scene Sketches
Once photographs have been taken, the crime CSI
must sketch the scene. The first sketch, the one
done while at the scene, is the rough sketch.
The rough sketch must contain an accurate
depiction of the dimensions of the scene and
show the location of all objects having a bearing
on the case.
21. Record the Scene
Objects are located in the sketch by
distance measurements from two fixed
points.
Each item in the sketch should be
identified with a number or a letter.
A legend should correlate the letter to
the items description.
Every sketch should include a compass
heading designating north.
22. Record the Scene
The Finished Sketch
The finished sketch is completed with care
and concern for aesthetic appearance.
The finished sketch must include and
reflect all information contained within the
rough sketch in order to be admissible in
court.
23. Record the Scene
Rough-sketch diagram of
a crime scene. Courtesy
Sirchie Finger Print
Laboratories, Inc.,
Youngsville, N.C.,
www.sirchie.com.
27. Record the Scene
Notes Note taking must be a constant
activity throughout the processing of the
crime scene.
The notes may be the only source of
information to refresh memory. The notes
must be sufficiently detailed to meet this
need.
Tape-recording notes at a scene can be
advantageous – detailed notes can be taped
much faster than they can be written.
28. Quick Review
Physical Evidence includes any and all objects
that can establish that a crime has been
committed or can link the crime and its victim or
perpetrator.
Forensic Science begins at the crime scene,
where investigators must recognize and properly
preserve evidence for laboratory examination.
The first officer to arrive must secure the crime
scene.
Investigators record the crime scene by using
photographs, sketches, and notes and make
preliminary examination of the scene as the
perpetrator left it.
