Crime Scene Investigation

Question 1

What is forensic science?

Answer 1

The application of scientific techniques to legal processes

Question 2

What is a crime scene?

Answer 2

• location/surrounding area where a crime has occurred

- focus point of investigation and primary source of information for investigation

Question 3

What are the definers of a crime scene?

Answer 3

• physical location (indoors, outdoors)
• primary/secondary location (primary: where the crime occurred, secondary: evidence found that links to primary)
• area size: macroscopic vs microscopic
• crime committed

Question 4

What is Locards exchange principle?

Answer 4

When two objects come in contact with one another, an exchange of matter takes place

Question 5

What factors affect the transfer of matter?

Answer 5

• pressure involved
• number of contacts
• ease of transfer (blood is easily transferred)
• form of evidence exchanged
• are of item involved in contact

Question 6

What is evidence?

Answer 6

Information given in legal preceedings to support fact or proposition

Question 7

What does evidence depend on?

Answer 7

Transfer and persistence

Question 8

What is the essential information generated from a crime scene?

Answer 8

• establish the identity of a victim or suspect
• establish links between the scene and people/objects
• provide leads of further enquiry
• focus investigation
• corroborate other events
  = leads to a reconstruction of events

Question 9

What are the 3 types of evidence?

Answer 9

1. Physical
2. Trace
3. Testimonial

Question 10

What is physical evidence?

Answer 10

Any material or items found in the crime scene of on the victim

Question 11

What is trace evidence?

Answer 11

Microscopic physical evidence that is found in small but measurable amounts

Question 12

What is testimonial evidence?

Answer 12

Written or verbal statements given to police, common evidence in rape or assault trials

Question 13

What are the 2 classes of evidence?

Answer 13

Direct

Circumstantial

Question 14

What is direct evidence?

Answer 14

First hand observations, includes eyewitness accounts, cameras and confessions

Question 15

What is circumstantial evidence?

Answer 15

Indirect evidence, may be used to imply or support and may link a suspect to a crime scene

Question 16

What are the branches of circumstantial evidence?

Answer 16

Physical, biological

Question 17

What are the investigation roles in Australia?

Answer 17

1. Uniformed officer
2. Detective
3. Scene of Crime officer
4. Forensic scientist

Question 18

What are the investigative roles in the US?

Answer 18

1. Police officer
2. Detective
3. Crime Scene Investigator
4. Medical examiner
5. Specialist

Question 19

What does a uniformed officer do?

Answer 19

Usually the first to the scene, secures crime scene

Question 20

What does a detective do?

Answer 20

Driving investigator and first called to scene by the uniformed officer

Question 21

What does the scene of crime officer do?

Answer 21

Responsible for evidence collection, documentation, secure transportation of evidence to the laboratory

Question 22

What does the forensic scientist do?

Answer 22

Receives evidence, undertakes scientific evidence, provides expert testimony in court, rare that they attend the crime scene

Question 23

What does the chain of custody do?

Answer 23

Details the movement of the evidence from the time it was collected to its appearance in court - any unknown times in the time period could indicate tampering

Question 24

What are the 5 steps of processing a crime scene?

Answer 24

1. Securing the crime scene
2. Crime scene survey
3. Crime scene documentation
4. Searching the crime scene
5. Collection of physical evidence

Question 25

What are the 3 scene cordons?

Answer 25

1. Hot zone 2. Warm zone 3. Cools zone

Question 26

What is the hot zone?

Answer 26

Encompasses the primary location of the crime, scene processing occurs here

Question 27

What is the warm zone?

Answer 27

Approx 100m around the hot zone

Question 28

What is the cool zone?

Answer 28

Area where media and pedestrians are permitted

Question 29

What is the role of the first officer at the crime scene?

Answer 29

- initial actions determine the success of the investigations - secures the scene against further disturbances since disturbance to the scene can not be reversed - looks at: safety, detains individuals involved, identifies areas to secure, and cordon

Question 30

What does securing the crime scene involve?

Answer 30

- large area - records status - restrict public - secure area

Question 31

What happens during a crime scene walkthrough?

Answer 31

- initial reconstruction - note evidence status: collection of some evidence must occur sooner than other pieces - note points of entry/exit - single point is determined - assess call out needs

Question 32

What are the different types of crime scene search patterns?

Answer 32

1. Spiral 2. Strip 3. Grid 4. Zone

Question 33

What does collection of physical evidence involve?

Answer 33

- document process - collect - maintain security of evidence - establish chain of custody - avoid contamination/cross contamination - obtain reference samples - obtain elimination samples if needed

Question 34

What should be documented at a crime scene?

Answer 34

- notification of personnel called to scene - arrival/departure of personnel - scene description (evidence, environment) - victim description

Question 35

What are the steps of the chain of custody?

Answer 35

1. Scene of crime officer 2. Transporting officer 3. forensic experts analysis 4. Secure storage (temperature and humidity controlled) 5. Return to long term police storage

Question 36

How does a crime scene reconstruction occur?

Answer 36

- evidence leads to hypotheses - hypotheses are tested - disproven hypotheses are thrown out, leaving a reconstruction theory - evidence = court case - no one piece of evidence a,one is enough to convict a suspect

Question 37

What are 6 common causes of evidence contamination?

Answer 37

1. Inappropriate collection methods 2. Deliberate tampering 3. Human error due to fatigue 4. Not using gloves when handling evidence 5. Packaging items of evidence together 6. Not using single use equipment

Question 38

What are two common areas during cross examination that a lawyer will attack regarding physical evidence?

Answer 38

Contamination and continuity