Transcript Crime Scene - Edwin G. Foreman College and Career Academy

The Crime Scene
Locard’s Exchange Principle
Every contact leaves a trace!
Whenever two objects come together they must affect
each other in some way. Something is likely to be
exchanged between them!
Physical Evidence - anything that
establishes a link between a
crime and a person
Principle of Individuality
Two objects may be indistinguishable, but no two
objects are ever identical. Things can be put into
classes or even individualized in useful ways.
Frye vs. Daubert
 Daubert
- “Does it work?”; Frye - “Do scientists
like and use it?”
 FRE 702 - If scientific, technical, or other specialized
knowledge will assist the trier of fact to understand the
evidence or to determine a fact in issue, a witness
qualified as an expert by knowledge, skill, experience,
training, or education, may testify thereto in the form of
an opinion or otherwise, if (1) the testimony is based
sufficiently upon facts or data, (2) the testimony is the
product of reliable principles and methods, and (3) the
witness has applied the principles and methods reliably
to the facts of the case.
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Search and Seizure
 Evidence
at a Crime Scene
 4th Ammendment to the Constitution
“The right of the people to be secure in their
persons, houses, papers and effects, against
unreasonable searches and seizures, shall
not be violated, and no warrants shall issue,
but upon probable cause, supported by oath
or affirmation, and particularly describing
the place to be searched, and the persons or
things to be seized.”
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Search and Seizure
 Evidence
at a Crime Scene
 4th Ammendment to the Constitution
“The right of the people to be secure in their
persons, houses, papers and effects, against
unreasonable searches and seizures, shall
not be violated, and no warrants shall issue,
but upon probable cause, supported by oath
or affirmation, and particularly describing
the place to be searched, and the persons or
things to be seized.”
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Search and Seizure
 4th
Ammendment to the Constitution
 Allowances
for Warrantless searches:
 the existence of an emergency.
 The need to prevent the immediate destruction
of evidence.
 A search of a person or property within the
immediate control of the person provided it is
made incident to a lawful arrest.
 A search made by consent of the person
involved.
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Collection of Evidence Legal Precedent
MINCEY v. ARIZONA (U.S. Supreme Court, 1978)
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Drug bust that went wrong and an undercover
police officer was killed.
Police spent 4 days searching and seizing evidence
Mincey arrested and convicted.
Supreme Court ruled evidence collected was
inadmissible because it was not from a proper
search and seizure.
Evidence taken without proper authority is probably
not legally admissible.
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Collection of Evidence Legal Precedent
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Michigan v. Tyler (U.S. Supreme Court, 1978)
Building destroyed by fire was put out in early AM.
Building left unsecured until 8 AM when a preliminary
search was done (for cause of fire).
Subsequent searches (at 4, 7, and 25 days) removed
additional evidence.
Tyler convicted of arson.
Supreme Court:
 “…entry to fight a fire requires no warrant, and that
once in the building, officials may remain there for a
reasonable time to investigate the cause of the blaze.
Thereafter, additional entries to investigate the cause of
the fire must be made pursuant to the warrant
procedures”
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Physical Evidence
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Must be recognized at crime scene.
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What relates to the crime and what doesn’t.
Must be properly collected, preserved and
controlled - from massive to microscopic
Only aids in investigations (evidence
doesn’t solve crimes by itself)
www.crime-scene-investigator.net
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Steps Taken at a Crime Scene
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Secure and Isolate the scene.
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Render medical help and arrest suspects (if
needed)
Preserve and protect evidence (isolate area)
Exclude unauthorized personnel
 Designate Officer in Charge (with authority)
 Establish boundaries
 Document site
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Collection of Evidence
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Evidence Team
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Personnel Duties and Responsibilities
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Team Leader
Photographer and Photographic Log Recorder
Sketch Preparer
Evidence Recorder/Evidence Recovery
Personnel
Specialists
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Evidence Team
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Personnel Duties and Responsibilities
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Team Leader
Assume control and access
 Determine search pattern and assignments
 Coordinate with groups involved
 Continuously evaluate work
 Release crime scene
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Evidence Team
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Personnel Duties and Responsibilities
 Photographer and Photographic Log Recorder
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Photograph entire scene (before and after entered)
Photograph victim, crowd, vehicles
Photograph evidence before it’s moved (including
fingerprints, casts, etc.)
Photograph evidence both in wide view (position at scene)
and close-up (with scale)
Possible use of video recording (does not replace still
photography
Prepare photographic log
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Capture Crime Scene
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Wide angle lenses are used to
distort the truth or emphasis it
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Details preserved
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Evidence Team
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Personnel Duties and Responsibilities
 Sketch Preparer
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Diagram area of scene (incl. orientation)
 Rough sketch - accurate dimensions, orientation and
location of evidence (from a fixed point)
 Finished sketch - aesthetic appearance (usually done
later sometime w/ CAD)
Set forth major items of evidence on sketch (with scale)
Make measurements (double check)
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Evidence Team
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Personnel Duties and Responsibilities
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Sketch Preparer
Rough Sketch
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Evidence Team
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Personnel Duties and Responsibilities
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Sketch Preparer
Finished Sketches
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Evidence Team
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Personnel Duties and Responsibilities
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Sketch Preparer
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Evidence Team
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Personnel Duties and Responsibilities
 Evidence Recorder/Evidence Recovery
Personnel
Have evidence photographed/sketched before
collection
 Describe evidence and location on container
 Package evidence
 Maintain chain of custody and evidence log
 Ensure proper safety of collection (e.g., infectious
materials)
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Evidence Team
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Personnel Duties and Responsibilities
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Specialists
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May include:
 Anthropologist
 Blood expert
 Bomb technicin
 Criminalist
 Engineer
 Entomologist
 Medical examiner
 Odontologist
 Surveyor
 Etc.
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Crime Scene Searches
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Thorough and Systematic
Unbiased and not overlook any relevant
evidence
Depends upon locale, area, type of crime
and conditions
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Crime Scene Searches
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Typical
search
patterns
Outer to
inner
Saferstein “Criminalistics”
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Collecting Evidence
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Cast’s of Physical Evidence
Blood Spatter Analysis
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What determines the type and manner of
collecting and preserving physical evidence?
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The nature of the
evidence
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Q. What type of evidence is to be
retrieved from a deceased victim for
examination in the crime laboratory?
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Clothing
Fingernail scrapings
Head and pubic hairs
“Orifice” swabs
Bullets
Hand swabs for gunshot residues
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Packaging Evidence
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Prevents any change after collection
Proper identification
Prevents cross contamination (separate
packaging)
Preserved intact (e.g., blood on clothes)
Crime scene safety
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Q. Who is
responsible for the
integrity of
handling the
evidence?
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Chain of Custody: is a
list of all persons who
came in possession of
an item of evidence.
Initials and date
should be recorded
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Chapter 2
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Physical Evidence
Legal Precedent
Evidence Team
Crime Scene Searches
Evidence Collection and Packaging
Chain of Custody
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