Presentation of evidence Flashcards
Adversarial System
Parties lawyers take the main responsibility for sifting through info and calling witnesses to present in court
Which system believes that the truth is best discovered via cross examination
Adversarial system
Which system believes truth is best discovered by cooperation in investigation with a neutral magistrate
Inquisitorial system
Inquisitorial system
Judge takes main responsibility for finding facts and sifting through info
Both sides present but no debate
three standards of proof
Reasonable and probable grounds
Beyond reasonable doubt
Balance of probabilities
Voir Dire
Trial within a trial
Can happen at any time during the trial
Is the evidence necessary
What starts the trial
Arraignment and plea
What makes evidence in court admissible
Mohan and Daubert Standards
Daubert Standards
Relevance
Scientific credibility
Reproducibility
Reliability
What is evidence
information put forward for the consideration of the trier of fact in Court
Rules of evidence
Efficient - in the interests of a speedy trial
Fair - probative value greater than prejudicial affect
Why can heresay evidence not be used in court
Because 3rd part evidence of what someone else said but someone else not called as a witness so cannot cross examine, therefore cannot test the truthfullness
Who decides what evidence will be called
Lawyers decide what evidence
Judges decide what evidence is admissible
Categories of evidence
Direct Evidence
Circumstansial evidence
Opinion evidence
Direct evidence
Evidence of actual offence/incident
real weapons
Circumstansial evidence
evidence that goes to prove circumstances that lead to certain events
Opinion evidence
Evidence put forward often on a hypothetical basis - opinion drawn from review of other evidence
What does both direct and circumstantial evidence have
Oral testimony
Real evidence
Recorded evidence under oath
Agreed statements of fact
Statutory presumptions
Is opinion evidence generally permissible
no
admissibility
to get the evidence to be allowed in to be heard by the trier of fact - requires a threshold reliability test
Reliability
once evidence is allowed it then the weight, if any that the trier of fact will give the evidence
Weight
how much stock/ belief the trier of fact puts in the evidence
Threshold reliability
not an evaluation of whether the opinion is correct, but it is supportable
Frye vs US
Concept: Admissibility of Novel Scientific Evidence
Key Contribution: Set out the “General Acceptance” test:
Scientific techniques must be generally accepted in the relevant field to be admissible.
Note: Eventually replaced in the U.S. by Daubert.
Used in a blood pressure lie detector test - ruled inadmissible because had not gained general acceptance
Daubert vs Merrell
Concept: Admissibility of Expert Scientific Evidence (U.S. law)
Key Contribution: Replaced Frye in the U.S. with a reliability and relevance test.
Daubert Criteria (non-exhaustive):
Has the theory/technique been tested?
Peer review/publication
Known or potential error rate
Existence of standards
General acceptance in the relevant scientific community
General Electric v Joiner
General Electric v. Joiner (1997)
Concept: Judicial Discretion on Admissibility
Key Contribution:
Appeal courts should not overturn a trial judge’s decision on admissibility unless there’s an abuse of discretion.
Courts may exclude expert opinions with an “analytical gap” between data and conclusion.
Kumho Tire co v Carmichael
Kumho Tire Co. v. Carmichael (1999)
Concept: Expansion of Daubert
Key Contribution:
Daubert applies to all expert testimony, not just “scientific” but also technical and other specialized knowledge.
Reinforced judicial gatekeeping role.
Weisgram v Marley co
Weisgram v. Marley Co. (2000)
Concept: Foundation of Expert Testimony
Key Contribution:
Experts must provide sufficient foundation for their opinions for evidence to be admitted.
Courts may exclude unsupported opinion evidence.
Dauberts two part admissibility test
Relibaility and relevance
R v Mohan
R. v. Mohan (1994), [2 S.C.R. 9]
Concept: Admissibility of Expert Evidence
Key Contribution: Established the 4-part legal test for admitting expert evidence in Canada.
Mohan Criteria:
Relevance
Necessity to assist the trier of fact
Absence of an exclusionary rule
Proper qualification of the expert
Probative vs Prejudice
probative value greater than prejudicial affect
Examples fo exclusionary rules
Disposition to commit the crime
Credibility
Character evidence
Legal opinions
Privilege
R v Abbey
Concept: Judicial Discretion, Gatekeeping, and Reliability
Key Contribution:
Reaffirmed the trial judge’s gatekeeping role.
Judges may exclude otherwise admissible evidence based on reliability concerns, time, and risk of confusion.
R v J
Concept: Admissibility – Judicial Scrutiny
Key Contribution:
Expert evidence should not be admitted too easily; frailties should be considered at the admissibility stage, not only at weight.
R v Trochym
Concept: Novel Science – Hypnosis Evidence
Key Contribution:
Hypnosis evidence excluded; underscores high scrutiny for novel science.
R v Bonython
R. v. Bonython (1984)
Concept: Admissibility Criteria for Expert Evidence
Handwriting and signature analysis
Key Questions for Admissibility:
Is the field of expertise generally accepted?
Is the expert sufficiently skilled to assist the court?
Makita v Sprowles
Concept: Expert’s Reasoning Process
Key Contribution:
The opinion must be based on admissible facts, and the reasoning process must be clear and linked to the facts.
R v turner
Concept: Necessity of Expert Testimony
Key Contribution:
Expert psychiatric evidence on motive excluded—not necessary for trier of fact.
R v Gilfoyle
Concept: Lack of Scientific Basis
Key Contribution:
Psychological profiling evidence excluded—no database or academic support to assess reliability.
R v Luttrell
Concept: Admissibility Despite Contradictions
Key Contribution:
Lip reading evidence admitted even though contradictory experts—judge cautioned the jury on reliability.
R v Kovats
Concept: Expert vs. Investigator Role Conflict
Key Contribution:
Lead investigator cannot also be expert witness due to risk of bias—roles are “incompatible”.
True or False: there are limits on the number of experts that can be called
True: BEcasue otherwise the trials would take too long, forces counsel to narrow down what is relevant
What is the limits of the # of experts that can be called in Canada
5 on either side
What is the limit of experts in Ontario
3 on either side
True or False: Affidavits may be allowed but the expert may still have to appear for examination and cross-examination
True: There may be some times where expert evidence is not contested or of such minor relevant does not require the witness to attend
True or False: You must give notice of intent to call an expert
True: so other party can take whatever investigation steps are necessary to properly consider potential expert testimony
How long do you have to give notice before you bring a witness to court
30 days
True or false: you must giv the name, area of expertise, CV and report of the expert prior to the being called as a witness
True
When does a prosecution witness provide a willsay statement
30 days before trial
When does a defense witness report a willsay
at close of crowns case
True or false: an expert must always sign an acknowledgement of their duty to be objective, non-partisan and be of service to the court
false: depends on category of law
True or false: remedy for failure to comply to the rules is most often an adjournment
True: the court still wants to hear all relevant evidence and the only time evidence should be kept from the trier of fact is if it is unreliable or obtained via such a transgression that allow it would bring the administration of justive into disrepute
True or false: It is not the report but the testimony of the expert that forms the substantial evidence of their opinion
True: viva voce evidence is what can be examined in chief and cross-examined reports are a tool for the expert to give notice of what their evidence will be and refresh their memory while on the stand
What must you have in order to provide opinion evidence in court and understand the utility and limitations of the evidence
A clear framwork about your work in a case and know answers to questions
What is the examination in chief
A time to tell the court of the story of your involvement in the case such that it is understandable to the trier of fact
Two purposes of forensic science
investigate and evaluate
Types of opinions forensic scientists provide
Categorial opinion
posterior probabilities
Exaplanations
Probabilitic interpretations
Categorial opinion
Includes factual opinions
Problematic due to subjectivity
Posterior probabilties
Starts with prior knowledge
include reference to probabilistic language
convey strength of outcome or experts belief in correctness
Hierarchies of propositions: Offence level
The proposition relates to the ultimate issue the court is deciding
Hierarchies or propositions: Activity-level
Proposition concerned with actions related to crime
HIerarchies of propositions: Source level
Proposition about investigation and analysis of forensic materials
of main interest to FS
R v France
Relates to expert evidence and the hierarhies of propositions
White burgess Langille inman v Abbott and Haliburton Co
Concept: Expert Independence & Impartiality
Key Contribution:
Lack of independence or impartiality can disqualify an expert.
These are part of the Mohan criteria (specifically under “proper qualification”).
Even perception of bias can lead to exclusion.
Conscious bias
Corruption
Acting as advocate for party
Intentially adapt opinion to benefit one side
Unconscoisu bias
Unconscoius considerations that influence accuracy opinion
Not intentionally done
Selection bias
lawyers only hire experts who serve their needs
Professional bias
taking a position to defned research or safeguard credibility
contextual bias
contaminatino of scientific opinion because of the contextual information to which scientist is exposed
Confirmation bias
Consequence of unwarranted contextual information
Expectation bias
Where contextual information drives an expectation as to what the outcome of analysis will be
Motivational bias
Professional motivation to contribute to solving a case overrides need to be scientifically pbjective
Anchoring
Where a piece of information emerges that appears to exert undue influence on the scientific interpretation of results
Time lapse bias
Where note-taking not contemporaneous may lead to biased account because of memory lapse
Brandon mayfield case
Concept: Confirmation Bias in Forensic Identification
Key Issue:
False fingerprint match in Madrid bombings
FBI confirmation bias, ignoring contradictory evidence
Led to public acknowledgment of forensic fallibility
Independence
to expert’s status or relationship with either party
Impartiality
attitude re: issues & parties
R v truscott
Concept: Misleading Expert Testimony & Disclosure Failures
Key Issues:
Time of death based on stomach contents misleading
Improper expert opinion on genital injury
Failure to disclose draft autopsy and other relevant facts
Eventually overturned based on new expert evidence
R v morin
Concept: Wrongful Conviction & Forensic Misconduct
Key Issues:
Tunnel vision
Flawed forensic science practices
Inadequate disclosure
Misuse of hair comparison evidence
Gave rise to kauffman recommendations
R v driskell
Concept: Expert Misconduct & Disclosure Failures
Key Issues:
Non-disclosure of exculpatory forensic findings
Unqualified expert witnesses
Reinforced need for independent, transparent forensic processes
Gouge inquiry
Concept: Forensic Pathology Reform
Key Themes:
Addressed misuse of expert status, unreliable science, bias, and systemic failures.
Noted lack of peer review, exaggerated conclusions, and poor lab practices (e.g., Dr. Charles Smith cases).
Recommended independent oversight and enhanced quality control.
Motherisk commission
found that this testing was “ inadequate and unreliable for use in child protection and criminal proceedings” and that the use of this evidence has “serious implications for the fairness of those proceedings”
What are demonstrative aids
Visual materials to help illustrte experts evidence by explaining events, procedures, results
Sally clark case
Two kids with SIDS
Multiple experts testified though not clear is meadows evidence is contradicted at trial
Cannings Case
Issue triple SIDS deaths in same family or smothering by a parent
Mother convicted
Options for dealing with conflicting opinions
Know alternate theories in the scientific area
Know where science, techniques, opinions converge and where they diverge
Cannings Case
Concept: Expert Disagreement & SIDS Misinterpretation
Key Issues:
Multiple child deaths (SIDS or murder?)
Conviction overturned due to scientific advances and expert reassessment
