Transcript FS - Day 16 Crime Scene Investigation - Evidence

New Seating Assignments
• Please find your seat
Agenda: 2/13
Homework:
1. Thank you note
2. Crime Scene Investigation Study Guide
1. Use PowerPoint for review
Test next week: Crime Scene; Evidence; Labs;
http://jsmithforensic.cmswiki.wikispaces.net/
• Warm-up: Read career article (Cornell notes and summarize)
• Officer Allen’s talk: Key information
• Crime Scene Investigation
• Evidence collection, packaging & chain of custody
• You as a Crime Scene Investigator –Day 1
• Pictures of a Crime Lab - Columbus, Ohio
A crime scene investigation consists of
recognizing, documenting, and collecting
evidence from the crime scene.
Multi-disciplinary approach
Officer Allen’s talk – Key Information
• TIME IS IMPORTANT.
• If you aren’t questioning the suspect
• Make sure the crime scene is BIG
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enough.
Separate any unwanted visitors from
the crime scene.
Get names, telephone numbers,
addresses & stuff.
He does NOT determine the body is
dead.
Protect the crime scene.
• GSR - Gun shot residue.
• If it’s a homicide, he calls Chief Monroe.
• Secure the crime scene.
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about the crime, you don’t have to read
him his Miranda rights.
Charlotte has a fully certified crime lab.
They re-create the crime scene.
We need a timeline of events that occur
during the investigation.
Mark areas & take pictures.
A detective directs the case.
PROCESSING A
CRIME SCENE
 Isolate and secure
the scene
 Document the scene
 Search for evidence
 Collect and
package evidence,
maintaining the
chain of custody
 Submit evidence to
the crime lab
COLLECTING AND
PACKAGING EVIDENCE
 One evidence collector - collects, marks,
seals, and preserves in a consistent manner
 Different types of evidence require specific or
special collection and packaging techniques
 Most fragile is collected and packaged first
 The body is the property of the coroner or
medical examiner. The collection of evidence
on the body is done by that department
Labeling evidence
Packaging Evidence
To identify
To preserve
To protect
Primary package
Secondary package
Subsequent packaging
CHAIN OF CUSTODY
There must be a written record of all people who
have had possession of an item of evidence.
 The evidence container must be marked for
identification
 The collector’s initials should be placed on the seal
 If evidence is turned over to another person, the
transfer must be recorded.
Chain of Custody - form
Chain of custody procedures
Crime Scene Reconstruction
CRIME SCENE RECONSTRUCTION
Hypothesis of sequence of events that occurred before and
through out the crime
Stages
 Data collection
 Hypothesis formation
 Examination, testing and analysis
 Determination of the significance of the
evidence
 Theory formulation
THE MEDICAL EXAMINER AND THE
CORONER
 A medical examiner is a medical doctor,
usually a pathologist and is appointed by the
governing body of the area.
 A coroner is an elected official who usually has
no special medical training.
 In four states, the coroner is a medical doctor.
MEDICAL EXAMINER’S
RESPONSIBILITIES
 Identify the deceased
 Establish the time and date of death
 Determine a medical cause of death—the injury or disease
that resulted in the person dying
 Determine the mechanism of death—the physiological
reason that the person died
 Classify the manner of death
 Natural
 Accidental
 Suicide
 Homicide
 Undetermined
 Notify the next of kin
INVESTIGATORS
“The wise forensic investigator will always remember
that he must bring all of his life experiences and logic
to find the truth. This means common sense, informed
intuition, and the courage to see things as they are.
Then he must speak honestly about what it adds up
to.”
—Dr. Henry Lee
Chief Emeritus for Scientific Services and the
former Commissioner of Public Safety for the state of Connecticut
You as a crime scene investigator
• Components:
• Description of a Well-known Case
• Description of the Duties of First Responder and Crime
Scene Specialists
• Your First Responder Story
• Your team will develop a story of when the first responder came on
to the scene. You will describe what she/he saw and then secured
and preserved the crime scene.
• Detailed Sketch of the Crime Scene
• Evidence Collected and How it was Preserved
THE CRIME LAB
A quick tour through the Columbus, Ohio
Police Department Crime Laboratory.
The crime lab: evidence storage and
analytical equipment
 Detailed and rigorous chain of custody of any evidence.
 Most sealed in plastic, but DNA evidence is not sealed in plastic since it
would degrade more quickly if sealed.
 Even plastic will allow some moisture loss, so drugs in plastic will lose
weight over time.
 Many labs now using a LIMS (laboratory information management system)
so evidence is barcoded, rather than have handwritten labels.
Documents lab
Primarily handles
falsified checks.
A lot of work that is
done in this lab is
visual assessment
by magnified
comparison of
signatures, inks
Fingerprint lab
 use fingerprint powder
and magnification to see
details.
 Fingerprints can reveal
drug use- metabolites
react with antibodies
used in fingerprint
powder.
Fingerprint lab
• Ninhydrin reaction with
proteins in fingerprint
requires reaction under
chemical hood.
• New labs have individual
hood spaces for each
reaction so there is no
possibility of transfer of
evidence
Alcohol lab
• Runs hundreds of
alcohol in urine tests at
a time.
• Head space gas
chromatography used to
determined percent
alcohol content
DNA laboratory
• Short tandem repeat (STR) process is done in this
lab and is most prevalent in US
• Work has to be done with care so that the material
is not contaminated with other DNA.
• How much is enough? A small stain on clothing, a
single drop of blood, the root of a hair. TRACE
evidence.
• DNA linked to FBI database
• National Integrated
Ballistics Information
Network (NIBIN) used to
identify bullets and
casings
Firearms
Integrated ballistics identification system
• Comparison microscope used to examine bullets and casings
to confirm if a particular gun was used.
Test fire
evidence
• Testing guns for the marks they leave on bullets and
casings.
Drugs lab
Drugs lab
Cocaine
and
marijuana.
First test
done is a
colorimetric
spot test.
Researching Maryland
• http://www.youtube.com/watch?v=1M_Kr1Y9etY
• Crime Scene Investigation and Forensic Anthropology -
YouTube