Week 2 - Introduction To Forensic Science

Question 1

Expert witness

Answer 1

An individual whom the court determines to possess knowledge relevant to the trial that is no required of the average layperson

Question 2

Locard’s exchange principle

Answer 2

Whenever two objects come into contact with each other, there is an exchange of materials between them

Question 3

Scientific method

Answer 3

A process that uses strict guidelines to ensure careful and systematic collection, organization, and analysis of information

Questions, hypotheses that can be and are empirically tested, analyze data, re-evaluate hypotheses

Allows science to be objective

Question 4

CSI effect

Answer 4

Dramatization of forensic science on TV has led to the belief that forensic evidence will be found at every crime scene and that a prosecutors case will always be supported by forensic evidence

In reality, most cases don’t have forensic evidence

Question 5

Definition of forensic science

Answer 5

The application of science to the criminal and civil laws that are enforced by police agencies in a criminal justice system

Question 6

Literary roots of forensic science

Answer 6

Sir Arthur Conan Doyle and his Sherlock Holmes

Applies serology, fingerprinting, firearms identification, document examination before it was adapted into real life investigations

Question 7

Pure science

Answer 7

Long history, scientific method, no specific aim, curiosity driven

Valid before forensic science became a thing

Question 8

Police driven science

Answer 8

Developed out of a specific police need, answer a police question, short history, might not have been tested, pattern evidence (fingerprints, bite marks, blood pattern analysis)

Question 9

Crime scene investigator

Answer 9

Sworn police officers, only work crime scenes, collect evidence to take to the forensic lab

Do not interrogate anybody, handle guns, or analyze evidence

Question 10

Forensic lab scientist

Answer 10

Civilians, analyze specimens, testify based on science, impartial, do not go to crime scene, scientific background, lab training

Question 11

Evidence

Answer 11

Collected by ident officers, taken to lab and given to forensic scientists, scientists analyze evidence, report to police, scientist present in court

Question 12

Evidence management unit

Answer 12

Catalogues evidence, every piece tagged with computer code so it can be monitored, destroyed evidence is logged, first step after crime scene

Question 13

Evidence recovery unit

Answer 13

First analysis step, each exhibit is examined, evidence is sent to appropriate lab section for analysis, search, isolate, collect evidence

Some evidence may go to multiple sections

Question 14

Forensic biology unit

Answer 14

Bodily fluids - semen, blood, tissue, hair

Identifies what it is, if its human, and who it came from

Called serology in USA

Question 15

Trace evidence (forensic chemistry) unit

Answer 15

Non-biological substances - paint, fibre, glue, drywall, gasoline

Crimes such as hit and run, break and enter, arson, terrorism have a lot of trace evidence

Question 16

Forensic toxicology unit

Answer 16

Toxins in bodily fluids, needles, pills, drugs

Things that can cause psychological effects

Question 17

Firearms and tool marks unit

Answer 17

Patterns evidence
Did this gun fire this bullet? Did this tool make this mark?
Only lab section that still employs police officers

Question 18

Forensic document examination unit

Answer 18

Questioned documents, handwriting/printing (forgery), machines that make documents, altered documents

Question 19

Scientists vs technicians

Answer 19

Scientists - oversee the work, perform interpretations, write reports, testify

Technicians - conduct the tests

Question 20

Three levels of forensic labs

Answer 20

Federal - FBI drug enforcement administrations laboratories, bureau of alcohol, tobacco, firearms, and explosives, US postal inspection service, defensive forensic science centre

State - networks

Local - county

Quality and services vary, basic and optional

In Canada - no specific section for photography and crime scene investigation and latent print analysis (done by Ident officers)

Question 21

Forensic science history

Answer 21

Only widely noticed more recently, there has been many famous scientists

1st forensic lab - 1910, Edmond Locard, Lyon France in 2 attic rooms
1st forensic lab in North America - 1914, laboratories de sciences judiciaries de medicine in Montreal

1923 - first US lab, 1931 - FBI lab

Question 22

Canadian lab systems

Answer 22

RCMP
Centre of Forensic Science
Laboratoire de Sciences

Question 23

RCMP

Answer 23

Three labs in Vancouver, Edmonton, and Ottawa
Vancouver - biology/dna, toxicology, firearms
Edmonton - biology/dna, toxicology, trace evidence
Ottawa - biology/dna, toxicology, firearms, trace evidence

Only deals with criminal cases for police

Question 24

Centre of forensic science

Answer 24

Toronto and Sault St. Marie
Full service - biology, trace, documents, photo, firearms, tool marks, toxicology

Attends to investigative agencies, defence, some civil

Question 25

Laboratoire de Sciences

Answer 25

Montreal, 1914, fbi is based on it
Full service - nDNA, mtDNA, toxicology, trace, documents, firearms, toolmarks, computer forensics

Attends to any organization in Quebec - police, corrections, coroners office, wildlife, commission of health, safety, liquor department etc…

Question 26

Forensic scientists in the lab

Answer 26

Pure scientists

A chemist may analyze gasoline, a forensic chemist may analyze gasoline from a hit and run

Analytical tests similar, but the purpose is different**

Question 27

Evidence in lab may go to…

Answer 27

One or many sections
Example: a bloody gun would go to biology then firearms

The anthrax letters went through 10 examinations

Question 28

The job of a forensic scientist

Answer 28

Submits reports to investigating officer
They are not there to prove the police case, they determine the truth and use forensic science as a tool

Question 29

The job of a forensic scientist

Answer 29

Submits reports to investigating officer
They are not there to prove the police case, they determine the truth and use forensic science as a tool

Question 30

Other forensic professionals

Answer 30

Ident officers - analyze fingerprints, pattern evidence like blood splatter
Forensic pathologists - autopsies
Consultants - anthropologists, botanists, dentists, entomologists, diatom specialists, odontologists

Question 31

Facts about eye witnesses

Answer 31

Common way to identify a criminal
Juries trust, but 71% of wrongful US convictions are based on eyewitness testimony
Ronald Cotton case

Question 32

Lay witness vs expert

Answer 32

Lay
Saw or heard something and will relay it to court
Can not give an opinion - like car was being driven too fast

Expert
Did not see or hear crime
Has analyzed evidence from crime
Interprets and gives opinion

Question 33

Expert witness opinion evidence

Answer 33

More than the average person’s knowledge
Specialized that goes beyond the knowledge of the trier of fact (R. V. Mohan)
Need education/training/research/experience
Knowledge relevant to case that will assist the trier of fact in understanding - this knowledge is not expected of an everyday person

Question 34

When is expert witness evidence used?

Answer 34

When the facts are not enough and the evidence is beyond understanding of the average person

Presented by prosecution or defence
Impartial - they are there to explain

Question 35

Expert witness in court

Answer 35

Not an expert until qualified by judge - expert is a legal term
Counsel presents qualifications of person they want to be an expert - opposing counsel may argue
Judge will deliberate
They are an expert until dismissed - must be re-qualified for each case

Question 36

Qualifications to be an expert

Answer 36

No set rules - education, training, experience varies
Up to judge - judge is not trained in any fields of science
Need to use vigilance - is the person actually qualified (Exxon Valdes case)

Question 37

Board certification

Answer 37

Set levels of education and experience
American academy of forensic sciences
Punitive measures
Expert witnesses have great responsibility
Unbiased testimony - only facts and truth and only on subjects they know

Question 38

Frye vs United States 1923

Answer 38

Frye standard
“The science must be generally accepted and well established”
Novel sciences excluded because not yet peer reviewed or published - problem because forensic science moves fast

Question 39

Federal rules of evidence - rule 702

Answer 39

Reliability of expert witness
- qualification of witness
- testimony factually based
- based on reliable methods and principles which were reliably applied

Question 40

Daubert standard

Answer 40

Judge became gatekeeper of if evidence is scientific, reliable, relevant, used scientific method

Guidelines
1. Has the theory been or can be tested?
2. Peer review and publication?
3. Whether known or potential error rates are acceptable?
4. Existence and maintenance of standards
5. Widespread acceptance in relevant scientific community

Question 41

Daubert trilogy

Answer 41

Daubert 1993
Joiner 1997 - exclude if gaps between evidence and conclusion
Kumho 1999 - judge still gatekeeper, scientific and technical knowledge

Question 42

Rules of evidence - Canada

Answer 42

Dulong vs Merrill lynch Canada 2006
- judge as gatekeeper

Mohan 1994
1. Relevant to the case
2. Necessary to assist trier of fact
3. Did not trigger any exclusionary rules
4. Presented by a properly qualified expert

Question 43

NAS report

Answer 43

National Academy of Science 2009
Scathing on pattern evidence - fingerprints (no error rates given), bootprints, bullet matching, bite marks, blood splatter
No scientific background to prove uniqueness - but are considered as such

Question 44

NAS recommendations that could impact Canada

Answer 44

All forensic labs should be independent of police
All practitioners should be certified
All coroners systems should be replaced with medical examiner systems

Question 45

PCAST 2016

Answer 45

Presidents council of advisors on science and technology - created “forensic science in criminal courts”

1. Clarity on scientific methods
2. Determine whether feature comparison methods were valid and reliable

Question 46

Trace evidence

Answer 46

Hair, fibre, body fluids, fingerprints, gasoline, paint, gunshot residue, bullets, writing
People leave trace evidence behind and take it away - Locard’s exchange

Question 47

Physical evidence

Answer 47

Identification - what is it? Use reliable and replicable tests
Comparison - with reference material - do two samples have a common origin?

Question 48

Characteristics of evidence

Answer 48

Impacts significance

Class
- associated with a group but not a single source
- can say a fibre came from a white t shirt, but cannot say which t shirt
- significance ranges from low to high

Individual
- “blood at scene comes from suspect A”
- high significance

Question 49

Low significance class evidence

Answer 49

Fibre at scene
Millions of people may have a shirt with the same fibre

Question 50

High significance class evidence

Answer 50

Rare fibre at scene
Less people would have the item, but still not unique
Significance depends on probability of evidence coming from somewhere else

Question 51

Class evidence - car paint

Answer 51

Cars have several layers of paint
Databases exist to determine colour, brand, year range
Paint chips can indicate information
Ownership records

Question 52

Probabilities

Answer 52

Must determine parent population - how many others?
Much evidence is mass produced
Class evidence can be cumulative - product rule states multiplying probabilities of each evidences lowers probability
Can almost be individualizing

Question 53

Individual characteristics

Answer 53

Individual = accidental
Identified to one source with high degree of accuracy
High significance - DNA, fingerprints

Question 54

Both individual and class characteristics

Answer 54

Car paint
Class - can identify group (yellow Honda civic)
Individual - actual chip may match to chipped portion on car

Bullet
Class - identify type of gun
Individual - minute striations on cartridge

Question 55

Value of evidence with class characteristics

Answer 55

Very, but cannot point to exact source

Useful when there are no eye witnesses or individual evidence

Question 56

Cautions with class evidence

Answer 56

Vital that examiner says its not individualizing
Jury translates “match” to mean “the one” but it could also match millions of others