Canadian Legal System Lie Detection
Outline:
- Comparing psychology & law
- Canadian legal system
- Lie detection
o Detecting deception Polygraph testing
Culture Clash
- Comparing psychology and law
o For 30-40 years there has been research about psychology
o There is a clash between the world of science and law
o They don’t agree since the goals are different
o In science the goals are true, because we want to know what is the truth, with law
and the legal system they want to tell you what to do.
1. Goals
- Psychology: Approximate truth
o Descriptive view
 We want to know what the truth is
- Laws: Approximate justice
o Prescriptive view
 What you can and can’t do
 It is to approximate justice
 Not to find the truth
2. Likelihoods
- The decision for the judge is only one of 2, guilty or not guilty, there is not innocence,
there is no grey area
- We can’t say this person if let go will harm someone but what we can say is, this person
shows aggression on these tests…
- Psychology: Probabilities
- Law: Absolutes
3. Approaches
- Psychology: Empiricism
o We have used objective scientific techniques
o Most psych is cold when approaching things in scientific ways
o They make their decisions by saying what does science say instead of looking at
their gut
- Law: Intuition
o They are very strongly driven by intuition
o A police would pull someone over based on how they feel, based on their
intuition, their gut
o A judge would say “what do I think”
4. Styles of inquiry
- Psychology: Objectivity
o Roots of science
o They have a hypothesis when doing an experiment
o The question is from her knowledge but the data from experiment will tell you the
answer
- Law: Advocacy
o People have roles that they have to follow
o Adversarial system
 People have positions to look for evidence, the lawyer is supposed to
defend her client so her job will all be around trying to prove it, the judge
will be put in the position of saying yes or now.
 Because in this system someone has to win or lose.
5. Methods
- Law: Past
o Their decisions are made based on previous decisions
o When legal system render decision, judges are not allowed to change the rules.
o They almost always make their decisions by looking what previous judges have
previously done or chosen
o stare decisis
 determining precedent
o precedent
 It is when saying “in the case of …”
 Judges rely on precedent
 They try to remind the judge
- Psychology: Future
o Because a lot of the technology, a lot of things are always changing
o Science is driven by change
o Info is always changing it is always evolving
Legal Systems
- All legal systems are: Categorical (everything can be categorized, like there are high and
less serious offences) (things are put from most to least important) and Hierarchical ()
- 2 main approaches
o Common law countries: Adversarial
 Canada is a common law country
 Common law is shared by every country that has every had a British
colony
 Countries who have a British origin, where there is a judge, a lawyer…
 There are laws and certain types of punishments that are written down.
 There are detailed rules that a judge has to apply, a judge almost never
asks questions
 Ex, USA, India, Australia
o Civil law countries: Inquisitorial
 The rest of western Europe a part from the UK, so like France for example
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It is known as an inquisitorial
A judge is a pathfinder not a referee
Judges have more of an individual power
A judge has detailed bases for making decision, he can ask questions to
the person
A judge will sit on the jury, so he has more control
Not on exam:
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Public law; her asking the court to pay for her tire, because she pays takes and the roads
should be good.
Private law is a contract, ex, a lease between you and your landlord.
Civil procedure: laws between citizens have been breached of a private law. Ex, taking
your landlord to court because he doesn’t do his obligations and one side of the party
wants to make things right
Criminal procedure: between and individual and a state, when an individual person has
violated a rule written by the state, and the state peruse charges against the the person that
broke the rule
Canadian Crime Statistics
- Police-reported crimes, 2016
- Non-violent crimes: 80% (1.5 million incidents) 1.2 million property offences (3,027 per
100,000)
- Violent crimes, 20% (1052 per 100,000 population)
o Most common is common assault, 71% of incidents
o Homicide: 611 homicides (1.7 per 100,000) Less than 0.2% of violent crimes
 There are underreported crimes as well so keep that in mind
 The city of Chicago has about more that 700, and that is more than in all
of Canada.
Common Law
- Roots: 11th century England
- When people hurt other people back then, they would hold their complaints then bring it
to the royal person, who is in charge of resolving the conflict
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The noble person would keep a list of all the conflicts and what he said the person has to
do
So people wouldn’t feel like it wasn’t fair, he would have to make decisions similar to the
ones that were made previously so things would be fair
So eventually the power to give laws was given to certain people
And as time marched on, people would elect those to make laws and decide on general
penalties for different types of laws
And this is what we have now
o Legislatures: statutes
 People in Ottawa make up the laws
o Interpretation: judges
 Those who interpret the laws as they see fit
Physician assisted death is now legal
Stare decisis ->Let the decision stand
o Central principle
 When a judge makes a decision he is supposed to be consistent with
similarly ranked judges
o Principles
 Have to follow the rules, and make the decision based on how other judges
would make decisions.
 Judges MUST follow decisions of highly ranked judges
o Advantages
 Helps to medicate, because these are highly trusted judges, so lower
judges will have to follow those who are higher
 A lawyer would be able to tell the defendant that, a person that did what
you did, previously got… so therefore what you might get would be…
PC-> prostitution, or trespassing, they are low level courts that hand out short precision
terms, low level fines
SC-> arson, kidnapping, murder, they are more important cases that out rank PC, they
can hand out more than 2 years in prison, of fines that are thousands of dollars
COA-> they make the decision to either support of overturn the other courts
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SCOC-> they make decisions as they seem fit, they are federal, and have the power to
change their minds, they only hear cases that they deem to be national importance, major
issues, same sex marriage, physician assisted suicide
Criminal Law
- 2 main elements:
o Actus Reus
 Latin for forbidden act
 what the defendant did is illegal
o Mens Rea
 Latin for guilty mind, evil mind
 we only prosecute people, if they have intended to commit a crime
- you may commit actus reus but not mens rea so you wont go to jail, like killing someone
by accident
- ex, a heart attack while driving and kills people, no mens rea, but there is actus reus.
- What about mental illness?
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Bail is a way of community policing, mom takes out a lawn, so she will make sure he will
show up
Preliminary proceeding to trial-> if you commit crime, crown puts charges against the
defendant
o Low level crime in Canada is called summary crime (vandalism, prostitution,
trespassing), goes to provincial court
o Indictment offence is murder kidnapping, it goes to superior courts
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Most cases in Canada don’t go to trial, about 90% contestant cases and they are resolved
without going to a court room
Before the trial is scheduled to start, the day before the court date, the crown prosecutor
will offer the defendant a lower charge for the crime committed which is also a lower
penalty, but the defendant would have to say that they are guilty.
The majority of cases are solved that way
Cases that are trailed at a provincial are lower than the superior (jury trials are often
here), when defendants are at a superior level sometimes there is the option for the
defendant to choose if they want just a judge or a judge and a jury. Some cases if large
enough like murder they will require jury
Judge or jury leave and make a decision then come back and say whether or not they are
guilty
If guilty, then there is a sentencing hearing, and the judge will collect info about his
criminal history, and assessments like psychiatric history, then the judge will hand down
a sentence
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If they are done one third of their prison term they can ask for parole, it is often during
the completion of two thirds 2/3 can be when they ask for parole and if they get it they
can leave
Lie Detection
- Importance: Police, judges, jurors
- A witness who is confused who says something false, might not be lying they might just
be confused
- Perjury
o When a witness lies on the stand can cause a fine and or time in jail
- Definitional: Intention, gain
o When lying there is something to gain -> freedom, you gain something out of it
- Challenge: Ground truth
o We don’t usually know 100% certainty if the person found guilty really did it, or
if the guilty person actually didn’t do it.
o All we work with is some approximation of truth
o Only in unusual standards do we have DNA, or a video
o We rely on the decision of the legal system, based on evidence and everything but
it may not be the golden truth
o It is how we define truth
Detecting Deception
- How do you detect a liar?
o Men and women are equal in the lies they tell
o It’s the kinds of lies
o Men make lies that make them look good, like their weight, the amount they make
o Women will lie to make others feel good
o Children as young at 3 know to look you in the eyes when lying because liars look
away (and that is called gaze aversion)
o Fidgeting or exaggerating
o Whether or not a liar shows a cue of lying depends on the lying and the person
o If they are used to lying, then they won’t show the signs of lying. So it depends on
the lie and the liar.
- Incorrect beliefs (Bond & DePaulo, 2008)
o Survey: 2500 people (just random people), 63 countries
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o 70% of all the people said there is a giveaway to lying, like blinking or playing
with your hair
o People in law enforcement never really know how good they are at catching liars.
o Liar’s stereotype:
 Non-verbal, verbal cues? You are more likely to spot a liar with verbal
cues than nonverbal
Meta-analysis: (Bond & DePaulo, 2006)
384 studies, 24 000 people
Accuracy
o Found that we are slightly saying that someone is telling the truth than saying that
they are lying by 54%
Verbal cues to lying?
- Criteria-Based Content Analysis (CBCA)
o There is really no proper evidence than knowing the liars, but there is more
evidence to verbal truths to liars
o When a legal worker, goes through listening to the person, and goes through
every word, in order to figure out a lie
- Some discriminators:
o Contextual embedding
 Fixing what you are saying
o Spontaneous corrections
o Admitting memory failure (truth tellers would often say I don’t know, they won’t
really remember, they will give random detail, they will be inconsistent, liars
though tend to give clear stories. It would be too smooth and polish.)
 Non-verbal cues are almost chance
- Accuracy in verbal cues -> truth: 76%
lie:68%
- Strategic Use of Evidence techniques
o Contradict known facts
 If the detective knows something, then they can catch the defendant in a
lie
o Reverse order
 Sometimes they ask the suspects in reverse order, when telling the truth
we are more likely to be able to give the order
 When lying it is more difficult
- Catching a liar is hard
- The best to know a liar is through verbal cues
Police and lie detection
- Othello- by Shakespeare
o He believes that his lover Desdemona is having an affair with Cassio, so he goes
to Cassio and asks him and Cassio says no so he kills Cassio. Then he goes to her,
and asks her and she says no, then she starts crying, and he interprets her crying as
that she is guilty, but she is crying because he has blood on him.
o Othello’s error
 Is that an emotion has only one source
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So an investigator ex, will say that someone nervous means they are guilty
but maybe they are just scared and innocent. And that means the
investigator committed Othello’s error
The murder of Meredith Kercher
Can investigators detect truthful and dishonest suspects? (Kassin et al., 2007)
o Kassin asked what they (police, officials…) thought their abilities were in lie
detection
o He asked 574 police, customs officials
o About 77% said they could detect whether or not a suspect was lying or telling the
truth
o Self-report
Accuracy in judging truthfulness study (Kassin, Meissner, & Norwick, 2005)
o He had Prison inmates’ taped confessions and showed them to the 2 groups
(undergrads vs police)
o Police detectives vs. undergrad students
o And asked them to view the videos of the prisoner’s confessions and see if the
suspect was lying or telling the truth
o Evaluate: Truth or lie
o Ground truth-> how researchers define what is the truth. Could be through video
tape evidence, or DNA evidence
o The graph below shows that the students were right 58.8% than the detectives
with 48.3%
o Police are performing worse, than chance
o They were then asked to rate their confidence, and students said they are not very
confident, but the police detectives were highly confident
o The police detectives are seeking some kind of a cue or give away that they might
have found useful in their career in the past few years they have been working.
 They are doing a conformation bias.
 Because they actually caught someone that was guilty ex, shaking
their leg. Then to them those that shake their legs are guilty
Improved lie-detection training study (Porter et al., 2000)
o Canadian parole officers
o Empirically-based training: Myths, feedback
o He trains them that how verbal cues are more helpful than non-verbal cues. He
provides police officers training on how to classify truth tellers and liars
o First day they watch videos of interrogations and got 40.5% accuracy
o Accuracy:
 Before training – 40.5%
 After training- 76.7%
o If you put an innocent person in jail it is way worst than letting 30 guilty people
walking
Physiological cues to lying?
- Historical lie detection
o Ancient Hindus: rice test
 They had suspects given dry rice, the suspect would then have to spit out
the rice after. If fluffy and moist then not liar, if dry and hard then liar
o Bedouins of Arabia: lick hot iron
 The suspect would answer certain question then the iron would be placed
on the suspects tongue, if burnt then liar, if not then not liar
- Sympathetic nervous system
o is involuntary movements, that are for fight or flight, energizing your body, and
mobilizing your bodies resources to fight or flight
o homeostasis-> consistency
Polygraph testing (shouldn’t be called a lie detectors test. Poly- multiple )
- Measures arousal:
o Heart rate
o Breathing rate & depth
o Blood pressure
o Galvanic skin response (sweat)
 There is minimal sweat from your finger tips
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Questioning procedures:
1. Comparison Questions Test (CQT)
- aka Control Questions Test
o he convinces the suspect that the polygraph test is great and really accurate
o and lets him know that they will do some questions
o he gives them the cards to shuffle (they are 7 cards) they are all the same card
o he then keeps asking him what card he gets and tells him that if he got a card that
he says to lie
o afterwards he looks at the polygraph test paper and tells them the card that they
held and makes sure to inform the suspect about the card that he got and that he
lied
o later he says that if he can tell which card he had then they will find out if the
suspect is lying or not, so what happens is that the suspect confesses right before
they start asking questions, if innocent then they will ask for the poly graph test
right away because they have nothing to hide
- 1940s, John Reid
- Pretest: ‘Stim test’
o Questions: Relevant (did you kill her) and control (where were you born)
o Compare differences in arousal (they want to see the graph lines if they change)
o Comparesent or control questions are not relevant in the actual crime (were you
born in Hamilton, did you ever shoplift)
o Accuracy-> Truth 72% and Lie 87%
 If flipped, this test makes 28% of innocent look guilty, and 13% of guilty
people get to walk, so the polygraph test is bias and more innocent people
are going to jail
o The faultiness in the polygraph is that those who are innocent are afraid and might
just be panicking
2. Concealed Information Test
- 1960s/1980s, David Lykken
o Aka ‘Guilty Knowledge’ test
o Multiple-choice
o The suspect is attached to polygraph machine, and he is asked questions where
only the offender would know and the police have an idea about but no one else
knows
o An innocent person wouldn’t know and would stay at the same rate, but the guilty
person would freak out as soon as the officer says something that only the suspect
who is guilty would know
o Accuracy-> Truth 96% and Lie 59%
 A reason why a guilty person could walk would be that maybe the
offender doesn’t know the details of his crime because of media depictions
 Most murders happen not because it was planned but out of complications
and budding heads
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Because the crime happened quickly and at a very emotional states, the
still haven’t understood who they killed until a few days, and they don’t
tend to remember well under high levels of stress
Concerns
1. Validity?
- Correct classifications in lab studies:
o You ask students to come into a lab and ask questions and tell them to lie about a
few things
o There are no consequences so they aren’t worried
o Guilty (liars) 85%, Innocent 77%
- Correct classifications in field studies:
o But when in a real situation, they are biased to those who are innocent
o Guilty (liars) 83%, Innocent 57%
Validity of polygraph testing
2. Conclusions: Inferences
o Any conclusion you reach about lying are just inferences, they are not
scientifically informed
3. Interpretation: Subjective
o One detective might say oh I don’t view it as a spike unless there is a difference in
sweat production and blood spiking, but other might say oh there is a spike in his
heart beating then he must be lying
4. Deceitful
o The test procedures are deceitful, those who are innocent are at the most
vulnerable
o The police can falsify DNA evidence or lie to the suspect about witness
information or anything
5. Countermeasures
o It is not terribly difficult to beat a polygraph
o By having a thumbtack on your foot and press on it to then make it spike on every
question
o If you put a thumbtack in your shoe and every time asked a question you press
down your foot your sympathetic nervous system will go up in response to it,
rendering results inconclusive
o You can have mental practices to help
- Main benefit?
o They induce confessions and show remorse before doing the test