Transcript Warm-Up - Cloudfront.net

DO NOW:
Slylock found bones in the trash.
The bull is an herbivore and only eats plants.
The raccoon is an omnivore and eats both plants and
animals. The raccoon is the trash tosser.
Welcome to 2nd period forensic science!
Pick up all materials from the “Do Now” boxes (in the cabinet)
Sit in your assigned seat:
Name
Seat Number
Name
Seat
Number
Amaro, Federico
1
Hopper-Aguirre, Tyler
Hyatt
19
2
Kelly, Alyssa Lynn
20
3
Lof, Darcy Elizabeth
21
Aviles Cruz, Annahi
4
Lopez, Alexandria Maria
22
Balcombe, Madison
Aremina
5
Marcum, Meriel Louise
23
Basaldua, Jennifer Allison
6
Mares, Eric
24
Basurto, Saul
7
Maxwell, Telisa De'shon
25
Belmares, Thalia
8
McGinnis, Ashley R.
26
Cortez, Cali Teresa
9
Noriega, Samantha B.
27
Davis, Desiree Nicole
10
Parker, Nathan J.
28
Delgado-Jaimes, Isael
11
Pena, Belkis S.
29
Dove, Ashley
12
Perez Medellin, Manuel
Fernando
30
Garces, Ashleigh Renae
13
Pericoli, Karigan Taylor
31
Ramos, Noemi
32
Stukes, Sharif Letike
33
Torres Gamez, Uriel
Adrian
34
Valadez, Adam Anthony
35
Zaragoza, Jesica A.
36
Amaro, Juan Jesus
Villarreal
Artieda, Alexander
Sebastian
Gonzales, Brandon
Alexander
Gonzalez, Isaiah
Contreras
14
15
Guevara, Giovanny
16
Gutierrez, Aryana Lucia
17
Hernandez-Cardoso,
Seydi A.
18
Distinguish
between
different types of
evidence
Distinguish
between
different types of
evidence
A – Locard’s Principle
2 – Deductive reasoning
3 – Testimonial evidence
4 – Physical evidence
5 – Trace evidence
6 – Direct evidence
7 – circumstantial evidence
8 – class evidence
9 – individual evidence
Create a frayer model – work
with your expert group.
You will share this with a 9person team.
I’ll choose the best ones to go on
our word wall.
Explain the 7 S’s
of CSI’s.
Create a poster that explains one of
the 7 S’s of Crime Scene Investigations.
Orange – securing the scene
Natural wood color – separating the witnesses.
Green – Scanning the `scene / seeing the scene
Yellow – Sketching the scene
Blue – searching for evidence
Red – securing and collecting evidence part 1
Purple – securing and collecting ev part 2 (evidence
packaging)
Crime Scene Team


A group of professional investigators, each trained in a variety of special
disciplines.
Team Members






First Police Officer on the scene
Medics (if necessary)
Investigator(s)
Medical Examiner or Representative (if necessary)
Photographer and/or Field Evidence Technician
Lab Experts
pathologist
serologist
DNA expert
toxicologist
forensic odontologist
forensic anthropologist
forensic psychologist
forensic entomologist
firearm examiner
bomb and arson expert
document and handwriting experts
fingerprint expert
Crime Scene Personnel
POLICE OFFICERS are typically the first to arrive at a crime scene. They are
responsible for securing the scene so no evidence is destroyed and detaining
persons of interest in the crime.
The CSI UNIT documents the crime scene in detail and collects any physical
evidence.
The DISTRICT ATTORNEY is often present to help determine if any search
warrants are required to proceed and obtains those warrants from a judge.
The MEDICAL EXAMINER (if a homicide) may or may not be present to
determine a preliminary cause of death.
SPECIALISTS (forensic entomologists, anthropologists, or psychologists) may be
called in if the evidence requires expert analysis.
DETECTIVES interview witnesses and consult with the CSI unit. They
investigate the crime by following leads provided by witnesses and physical
evidence.
Source: http://science.howstuffworks.com/csi.htm
7 S’s of Crime Scene Investigation
1. Securing the Scene
– Responsibility of the first responder
– Safety of everyone in vicinity is top priority
– Evidence preservation is second priority
2. Separating the Witnesses
– Avoids collusion
– Questions that should be asked include:
Secure the Crime Scene
Questions for Witnesses
•
•
•
•
•
•
A) When did the crime occur?
B) Who called in the crime?
C) Who is the victim?
D) Can the perpetrator be identified?
E) What did you see happen?
F) Where were you when you observed the
crime scene?
3. Scanning the Scene
Determine if it is a primary or secondary scene
• Primary crime scene – The original location of a
crime or accident.
• Secondary crime scene – An alternate location
where additional evidence may be found.
Where should photos be taken?
Wear protective gear to prevent
contamination of crime scene
4. Seeing the Scene
– CSI’s need to see the scene
– Photos with and w/out rulers should be taken
– Triangulation of stationary objects should be
included for reference points
Photographing the Scene
Take at least 3 shots:
1. Midrange shot: show how the item is related to
its surroundings
2. Close-up: bring out details of item
•
•
Take 2 close-up shots if marking or measuring device
is used
One shot without device, one shot with device
Mark Evidence with Tents
5. Sketching the Scene
– Position of body (if any) and any other evidence
– Should be measured from 2 immovable landmarks
– North should be labeled and a scale should be
provided
– Positions of furniture, doors (inside), shrubs, trees
(outside) should be included
6. Searching for Evidence
– Spiral, grid, linear or quadrant patterns should be
used
7. Securing and Collecting Evidence
– Proper packaging, sealing and labeling is vital
• Liquid/Arson remains - airtight/unbreakable containers
• Biological evidence - breathable containers so it can dry
out
• Dry item - bindle  plastic or paper container
– Must include a evidence log and chain of custody
Packaging Evidence
Bindle or Drugests Fold: folded paper used to hold
trace evidence
1. Crease a clean paper and place the
evidence in the X position (as shown
above).
2. Fold in the left and right sides, and
then fold in the top and bottom.
3. Put the bindle into a plastic or paper
evidence bag affixing a seal over the
opening.
4. Write your name on the seal.
Chain of Custody
• Essential to maintain in order to present credible
evidence in court, a chain of custody log is essential.
• Original collector: bags evidence properly, labels it
properly, seals it and signs the sealed edge.
• Next person to receive evidence signs that they
received it (lab technician for example); lab tech
opens sealed container at a location other than the
sealed edge; after examination, tech repackages ,
signs log and reseals with new tape/signature.
Chain of Custody
– Indicates every person who has handled the
evidence
– Log must be attached to packaging
Evidence Log
– Case number
– Item inventory number
– Description of evidence
– Name of suspect
– Name of victim
– Date/time of recovery
– Signature of person
recovering the evidence
– Signature of any witnesses present during
collection
Chain of Custody
• Importance of Chain of Custody
Packaging Dry Evidence
• After evidence has dried, it is packed in a
paper bindle (aka druggist’s fold)
• Then it can be put into a plastic or paper
container, labeled with evidence tag, sealed
and taped with the collector’s signature across
the taped edge.
• Control samples must also be obtained from
the victim for exclusion purposes.
Evidence Analysis
• Done in forensic labs – the largest is the FBI
crime lab
• Forensic lab technicians are specialists – unlike
what you see on tv
• Results sent to lead detective who then
attempts to reconstruct the crime scene
Investigating the Evidence
Drug Chemistry – Determines the presence of controlled substances and the identification
of marijuana
Trace Chemistry - Identification and comparison of materials from fires, explosions, paints,
and glass.
Microscopy – Microscopic identification and comparison of evidence, such as hairs, fibers,
woods, soils, building materials, insulation and other materials.
Biology/DNA – Analysis of body fluids and dried stains such as blood, semen, and saliva.
Toxicology – Tests body fluids and tissues to determine the presence of drugs and poisons.
Latent Prints - Identification and comparison of fingerprints or other hidden impressions
from sources like feet, shoes, ears, lips or the tread on vehicle tires.
Ballistics (Firearms) – Study of bullets and ammunition through the comparison of fired
bullets, cartridges, guns, and gunpowder patterns on people and objects.
Toolmarks – Examines marks left by tools on objects at a crime scene or on a victim, such
as a hammer used to break a door or a screwdriver used to pick a lock.
Questioned Documents - Examination of documents to compare handwriting, ink, paper,
writing instruments, printers, and other characteristics that would help to identify its origin.
What evidence would you collect and how?