Chapter 2: Crime Scene Investigation & Evidence Collection

Question 1

What is the goal of a crime scene investigation?

Answer 1

• to recognize
• to document
• collect evidence

Question 2

When 2 people come into contact w/ each other a physical transfer occurs. These transferred materials are called _______.

Answer 2

Trace Evidence
- can be found on both ppl (or objects) bc of the cross transfer
Ex. hair, pet hair, paint, chemicals, soil/pollen, finger prints, etc.

Question 3

Who is Dr. Edmond Locard?

Answer 3

• responsible for trace evidence
• direction of the 1st forensic lab in France
• Locard’s Exchange Principle

Question 4

What happens during a cross transfer?

Answer 4

• a cross transfer of physical evidence occurs
• the intensity, duration, and nature of the materials in contact determine the extent of the transfer

Question 5

What are the 2 Types of Evidence?

Answer 5

Direct Evidence
Circumstantial Evidence

Question 6

Direct Evidence

Answer 6

1st hand observations
- eyewitness accounts
- police dashboard cameras
- confessions

Question 7

Circumstantial Evidence

Answer 7

Indirect used to imply a tact but doesn’t prove
- provides 2 link between a crime scene and suspect
- trace evidence is an example
- 2 types

Question 8

What are the 2 Types of Circumstantial Evidence?

Answer 8

Physical and Biological

Question 9

Physical Circumstantial Evidence

Answer 9

• all types of evidence exempt for fingerprints reduces the # of suspects to a small specific group of ppl
  Ex. fingerprints, footprints, shoe prints, tool marks, bullet shell casings

Question 10

Biological Circumstantial Evidence

Answer 10

Any body fluids
Ex. blood, saliva, vomit, etc

Question 11

Class Evidence

Answer 11

narrows an identity to a group of persons or things
Ex. ABO blood type found at a crime excludes all other blood types

Question 12

Individualized Evidence

Answer 12

narrows down to a single person or thing

Question 13

Who is involved in a crime scene investigation?

Answer 13

Police officers
District Attorney
Crime Scene Investigator
Medical Examiner
Detectives
Specialists

Question 14

Police Officers

Answer 14

1st to arrive

Question 15

District Attorney

Answer 15

may be present if a search warrant is necessary

Question 16

Crime Scene Investigator

Answer 16

• sketch
• record evidence
• collect evidence
• take pictures

Question 17

Medical Examiner

Answer 17

coroner determines the cause of death

Question 18

Detectives

Answer 18

interviews witnesses & talks to investigators about the evidence

Question 19

Specialists

Answer 19

• expertise
  Ex. entomologists & forensic psychologists

Question 20

Steps to Processing a Crime

Answer 20

1. Secure the Scene
2. Separate the Witnesses
3. Scanning the Scene
4. Seeing the Scene
5. Sketching the Crime Scene
6. Searching for Evidence
7. Securing & Collecting Evidence

Question 21

1. Secure the Scene

Answer 21

• done by the 1st responding officer
• safety
• preservation of evidence
• prevent authorized ppl from entering the scene
• keep a log of who enters the scene
• may call for more help

Question 22

2. Separate the Witnesses

Answer 22

• witnesses should not talk to each other
• avoids a false story
• when did the crime scene occur?
• where were you?
• who called 911?

Question 23

3. Scanning the Scene

Answer 23

• to determine where the photo should be taken
• establish if there is a primary and secondary crime scene

Question 24

Primary Crime Scene

Answer 24

location of the crime
Ex. Nicole Simpson murder place

Question 25

Secondary Crime Scene

Answer 25

location related to the crime where evidence is found Ex. OJ's gloves outside of other house

Question 26

4. Seeing the Scene

Answer 26

- overall pictures - close up pictures - w/ or w/o rulers

Question 27

5. Sketching the Crime Scene

Answer 27

*- include case #, date, location, and investigator's name - accurate rough sketch should be made - note the position of the body & evidence - north should be labeled - scale included - if outside include the position of trees, cars, hedges & other structures - more accurate copy is made for court at a later date

Question 28

6. Searching for Evidence (search patterns)

Answer 28

4 Search Patterns - 1. Grid - 2. Linear - 3. Quadrant or Zone - 4. Spiral

Question 29

7. Securing & Collecting the Evidence

Answer 29

- all evidence needs to be packaged, sealed & labeled - liquids & arson remains should be stored in airtight unbreakable containers - moist biological evidence should be stored in breathable containers so it can dry out - wet evidence should never be packaged wet - evidence should be entered into log

Question 30

How do you package dry evidence? (lab)

Answer 30

- crease a clean paper & place the evidence in the x position - fold in the left & right sides, and then fold in the top & bottom - called a bindle - put the bindle into a plastic or paper evidence bag placing a seal over the opening - write your name on the seal

Question 31

What info needs to go into the evidence log? (lab)

Answer 31

- Case # - Item Inventory # - Description - Name of suspect - Name of victim - Date & time recovery - Signature of the person who recovered the evidence - Signature of any witness present during the collection

Question 32

Analyzing the Evidence (Who does it?)

Answer 32

- Done by a lab - FBI crime lab - Lab techs have specialists - Lab results sent to detectives - Results lead to crime scene reconstruction

Question 33

Chain of Custody

Answer 33

- important to present credible evidence in court - a person bags the evidence, marks it for identification, & signs across the sealed edge - signed over to a lab tech, who opens it, but not at the sealed edge - after analysis, lab tech puts the evidence back in the bags, seals it in another bags, and signs the evidence bag

Question 34

Crime Scene Reconstruction

Answer 34

- forms a hypothesis about the sequence of events - how does the evidence fit? - evidence is compared w/ witness statements? - provides connections - establishes identities - confirms testimony - can be used to find s/o guilty or innocent Ex. JonBenet house reconstruction, staircase

Question 35

How to Determine if a Crime Scene is Staged

Answer 35

- evidence doesn't match witness testimony - arson - suicide/murder - bugerly - treat all as death investigators - do the wounds match teh type of weapon > easily be self-inflicted? - establish a profile of the victim - evaluate the behavior of the victim/suspect - corroborate statements w/ evidence - reconstruct the event - conduct all forensic examinations to determine the facts of the case