- 1 Findings of Fact
- 2 Credibility and Reliability
- 3 Factors in Evaluating Credibility and Reliability
- 4 Special Types of Testimony
- 4.1 Credibility of Accused (The W.D. Test)
- 4.2 Credibility of Persons from Other Cultures
- 4.3 Credibility of Children
- 4.4 Adults Testifying to Events Occurring When a Child
- 4.5 Credibility of Police Officers
- 4.6 Credibility of the Complainant or Victim
- 4.7 Credibility for Other Types of Witnesses
- 5 Related Topics
- 6 See Also
Findings of Fact
Analysis of Testimony
Tools of Analysis
When considering testimony evidence, its value comes down to four factors:
- narration, and
Evidence Not to be Analyzed Separately
Facts should not be examined separately and in isolation to the standard of proof beyond a reasonable doubt.
However, beyond determining whether the evidence on the whole proves guilt beyond a reasonable doubt, "it is for the trier of fact to determine how to proceed".
No Choosing of Stories
When confronted with two contradictory stories, a judge does not need to make a finding of fact as to which story is correct.
An approach that permits choosing of stories would "erode" the presumption of innocence and standard of proof beyond a reasonable doubt. However, it is not an error to make "finding of credibility as between the complainant and the accused" as long as all the steps of further analysis are taken. It is only in error should the judge treat the task as complete once a finding of credibility as between the complainant and accused.
Guilt should not be based a credibility contest or choice between competing evidence.
- see Admissions of Fact
- Kenneth S. Broun et al., 2 McCormick on Evidence, (6th ed.) (USA: Thomson/West, 2006), §245, at p. 125 and R v Baldree, 2012 ONCA 138 (CanLII) at para 43
R v Morin, 1988 CanLII 8 (SCC),  2 SCR 345 ("facts are not to be examined separately and in isolation with reference to the criminal standard")
R v Narwal, 2009 BCCA 410 (CanLII),  BCJ No. 1941 (C.A.), at para 88
R v Menow, 2013 MBCA 72 (CanLII)
- Morin, supra at para 40 ("during the process of deliberation the jury or other trier of fact must consider the evidence as a whole and determine whether guilt is established by the prosecution beyond a reasonable doubt. This of necessity requires that each element of the offence or issue be proved beyond a reasonable doubt. Beyond this injunction, it is for the trier of fact to determine how to proceed")
- R v Avetysan, 2000 SCC 56 (CanLII) at p 2
R v DW, 1991 CanLII 93 (SCC),  1 SCR 742, at pp. 757-8 (SCR) or 409 (CCC)
R v Avetsyan, 2000 SCC 56 (CanLII), (2000), 149 CCC (3d) 77 (S.C.C.) at paras 18-22
R v JR, 2014 QCCA 869 (CanLII),  Q.J. No. 3957 (C.A.), at para 38 (the judge “cannot simply choose one over the other. That would in effect lower the prosecution's burden from proof beyond a reasonable doubt to proof on the balance of probabilities”)
- R v Chittick, 2004 NSCA 135 (CanLII), at paras 23-25
Chittick, ibid. at para 23-25
R v MDR, 2015 ONCA 323 (CanLII)
R v Fleig, 2014 ABCA 97 (CanLII), at para 24, ("primary concern of the framework in W(D) is that a trier of fact should not line up the Crown and defence evidence and select one over the other.")
R v ST, 2015 MBCA 36 (CanLII), (“a trial judge cannot render a verdict in a criminal case by the process of simply deciding which competing narrative of events he or she prefers; that is the so-called ‘credibility contest’ error.”)
Acceptance of Evidence
Selective Acceptance of a Witness' Evidence
Evidence before a judge are not facts. The judge has the power to hear evidence from which factual conclusions may be made. The testimony of a witness is not a fact until the trier finds it as so. It is only for the trier to decide. The trier may accept all, some, or none of what a witness says. If the witness is not believed on an issue, the evidence supporting it must be rejected. 
Of the evidence accepted, the trier-of-fact may associate different weights to individual parts of the evidence.
Finding of Facts Limited to Issues of Dispute
It must be remembered that when assessing evidence heard at trial, it is not the court's role to "resolve the broad factual question of what happened". The judge is only obliged to decide "whether the essential elements of the charge have been proven beyond a reasonable doubt."
The court does have a limited power to edit statements and other forms of evidence as part of its jurisdiction over the trial process. This is usually applied where the evidence is unduly prejudicial.
Consequence of Findings
Reliance on Evidence
The trier-of-fact may only convict where there has been "acceptable credible evidence" that was found to be factually correct. If there is "contradictory evidence" on an element of the charge the accused must be given the benefit of that doubt even if the accused evidence is rejected.
No Need for Corroboration
In appropriate cases, regardless of the offence, it is reasonable to find guilt based solely on the evidence of a single witness.
R v DAI, 2012 SCC 5 (CanLII),  1 SCR 149, at para 72
R v Francois, 1994 CanLII 52 (SCC),  2 SCR 827, at p. 837 or para 14
R v BC, 2011 ONCA 604 (CanLII), at para 5 leave refused
R v MR, 2010 ONCA 285 (CanLII), at para 6
R v DR, 1996 CanLII 207 (SCC), 107 CCC (3d) 289 (S.C.C.) per L’Heureux-Dube J. (dissenting in result), at p.318
R v Hunter,  O.J. No. 4089 (ONCA), at para 5
R v Abdullah, 1997 CanLII 1814 (ON CA),  O.J. No. 2055 (C.A.), per Carthy and Goudge JJA at paras 4 to 5
R v Mathieu (1994), 1994 CanLII 5561 (QC CA), 90 C.C.C. (3d) 415 (Que. C.A.) at para 61 aff’d 1995 CanLII 79 (SCC),  4 S.C.R. 46, per Lamer CJ, ("...triers of fact remain free, as they have always been in the past, to accept all, part or none of the evidence of any witness... . The evidence of each witness must be considered in the light of all the other evidence.")
- R v Morin, (1987), 36 CCC (3d) 50 per Cory J.A.
R v Howe, 2005 CanLII 253 (ON CA), (2005), 192 CCC (3d) 480 (Ont. C.A.), at para 44
R v Mah, 2002 NSCA 99 (CanLII) at para 41
- R v Dubois, (1986), 27 CCC (3d) 325 (ONCA)(*no CanLII links)
- R v Campbell, 1995 CanLII 656 (ON C.A.)
R v Chan, 1989 ABCA 284 (CanLII)
R v CWH, 1991 CanLII 3956 (BC C.A.)
R v Miller, 1991 CanLII 2704 (ON C.A.)
R v AG, 2000 SCC 17 (CanLII),  1 SCR 439, at pp. 453-4
R v Vetrovec, 1982 CanLII 20 (SCC),  1 SCR 811, at pp. 819-820
On appeal, findings of credibility cannot be interfered with unless the "assessments ... cannot be supported on any reasonable view of the evidence."
An appellate court should not interfere with credibility assessments "except in very particular circumstances".
Where a legal error is made in assessing credibility, there is no deference and may require intervention.
The finding of a fact where there is no evidence to support it is reviewable as a question of law on a standard of correctness. The same goes for interpreting the legal effect of a finding of fact.
Finding of fact based on an irrelevant consideration is a question of law and reviewable on a standard of correctness.
Credibility and Reliability
"Credibility" vs "Reliability"
Credibility refers to the witness's ability to be "honesty or veracity". Reliability refers to a witnesses "accuracy". A discreditable witness cannot be reliable. However, a credible witness may still be make an honest mistake.
Accuracy of a witness considers their ability to (1) observe, (2) recall and (3) recount to events at issue.
A credible witness can give unreliable evidence, but a non-credible witness cannot give reliable evidence.
Given that witnesses are not presumed to tel the truth, the trial judge has no obligation to accept any uncontradicted evidence given by the witness. In fact, uncontradicted evidence may be rejected by the judge on the basis of "reason, common sense and rationality".
R v Sanichar, 2012 ONCA 117 (CanLII), at para 69
R v HC, 2009 ONCA 56 (CanLII), 241 C.C.C. (3d) 45, at paras. 41-44
R v JVD, 2016 ONSC 4462 (CanLII) at para 92 per Tzimas SCJ
R v Gostick, 1999 CanLII 3125 (ON CA),  O.J. No. 2357 at paras 15 and 16
R v Vickerson  O.J. No. 2798, at para 28 (ONCA)
R v SC, 2012 CanLII 33601 (NL SCTD),  N.J. No. 210, 324 Nfld & P.E.I.R. 19
HC, supra at para 41
HC, supra at para 41
R v Cunsolo, 2011 ONSC 1349 (CanLII) at para 228 to 232
R v Francois, 1994 CanLII 52 (SCC),  2 SCR 827, at para 14
D.R. et al. v The Queen, 1996 CanLII 207 (SCC), (1996), 107 CCC (3d) 289 (S.C.C.) per L'Heureux-Dubé J. dissenting in result at p. 318
R v M.R, 2010 ONCA 285 (CanLII) at para 6
R v Hunter, 2000 CanLII 16964 (ON CA),  O.J. No. 4089 (C.A.) at para 5
R v Abdallah, 1997 CanLII 1814 (ON CA),  O.J. No. 2055 (C.A.), Carthy and Goudge JJ.A, at paras 4, 5
R v Cook, 2010 ONSC 1188 (CanLII)
Cunsolo, supra at para 228
R v Howe, 2005 CanLII 253 (ON CA),  O.J. No. 39 (C.A.), at para 44
R v Clark, 2012 CMAC 3 (CanLII), per Watt JA, at para 41
Clark, ibid. at para 41
Analysis of Credibility
Evaluating evidence involves the assessment of a witnesses credibility and reliability. These are distinct but related concepts referring to the witness' veracity (the former) and accuracy (the latter). There can be significant overlap. "Testimonial reliability" or "reliability" can often mean or include credibility.
Evaluating credibility is not a scientific or intellectual process.There are no hard and fast rules to apply. It is not simply the application of a set of rules as much as it is "a multifactoral evaluation of the witness that includes factors such as the witness’ intelligence, demeanor, ability and capacity to observe and remember, and the intent of the witness to be truthful or deceive".
It involves a "complex intermingling of impressions" based on observations in the context of "independent evidence" and "preponderance of probabilities" that are recognized as reasonable.
The process can often defy verbalization, particularly where "complex intermingling of impressions that emerge after watching and listening to witnesses and attempting to reconcile the various versions of events."
Any case that turns on the issue of credibility between two witnesses, the main question is whether the Crown has proven the case beyond a reasonable doubt. Where significant inconsistencies or contradictions exist in the complainant's evidence, the trier-of-fact must assess the evidence carefully.
A failure to properly articulate the credibility concerns may amount to a reversible error.
A failure to cross-examine a witness on a point that is significant to an important issue can be taken into account when evaluating credibility.
Totality of Evidence
The evidence of a witness must always be assessed "in light of the totality of the evidence adduced in the proceedings".
This involves considering the "whole tapestry" (or the "whole scope and nature") of the evidence.
It is an error of law to evaluate reliability and credibility on the basis of individual pieces of evidence without looking at the totality of the evidence.
R v Morrissey, 1995 CanLII 3498 (ON CA), (1995), 22 O.R. (3d) 514 at para 33 per Doherty J.A.
R v N.L.P., 2013 ONCA 773 (CanLII) at para 25
R v Woollam, 2012 ONSC 2188 (CanLII) at para 90-111 gives detailed canvassing of use of term "reliability" also referring to see R v Murray 1997 CanLII 1090 (ON CA), (1997), 115 CCC (3d) 225 (Ont.C.A.)
R v Thurston,  O.J. No. 2011 (Gen. Div.)(*no CanLII links)
R v KTD,  O.J. No. 2890 (S.C.J.)
- R v Gagnon 2006 SCC 17 (CanLII) at para 19 to 21
R v Mesaros, 2014 ONSC 3445 (CanLII), at para 21
R v Wadforth, 2009 ONCA 716 (CanLII) at paras 66 to 67
- R v White,  SCR 268, 1947 CanLII 1 (SCC)
R v SIC, 2011 ABPC 261 (CanLII) at para 19
R v Lunz, 2013 ABQB 150 (CanLII)
R v White, 1947 CanLII 1 (SCC),  SCR 268 at paras 8‑10
R v JFD, 2017 BCCA 162 (CanLII), at para 38
Mesaros, supra at para 21
See: R v Gagnon, 2006 SCC 17 (CanLII),  1 SCR 621, at para 20
R v Dinardo, 2008 SCC 24 (CanLII),  1 SCR 788, at para 26
R v REM, 2008 SCC 51 (CanLII),  3 SCR 3, at para 49
Wadforth, supra at para 66
R v H(W), 2013 SCC 22 (CanLII),  2 SCR 180, at paras 39-40
R v Wylie, 2012 ONSC 1077 (CanLII),  O.J. No. 1220 (S.C.J)
R v Selles (1997), 1997 CanLII 1150 (ON CA), 101 O.A.C. 193 (C.A.), at pp. 207-8
R v NM,  O.J. No. 1715 (C.A.) (QL) at para 1
Wylie, supra at para 84
- R v Braich, 2002 SCC 27 (CanLII) at para 23
R v Carter, 2005 BCCA 381 (CanLII)
R v Paris, 2000 CanLII 17031 (ON CA), 150 CCC (3d) 162 (Ont. C.A.)
Clark, supra at para 40
R v Cameron, 2017 ABQB 217 (CanLII) at para 28
Faryna v Chorny, 1951 CanLII 252 (BC CA) ("The credibility of interested witnesses, particularly in cases of conflict of evidence, cannot be gauged solely by the test of whether the personal demeanour of the particular witness carried conviction of the truth. The test must reasonably subject his story to an examination of its consistency with the probabilities that surround the currently existing conditions. In short, the real test of the truth of the story of a witness in such a case must be its harmony with the preponderance of the probabilities which is a practical and informed person would readily recognize as reasonable in that place and in those conditions.")
- JMH, 2009 ONCA 834 (CanLII) – Judge incorrectly acquitted the accused on the basis that a poem of the sexual salt victim referencing doubt amounted to doubt on non-consent
Disbelief vs Fabrication
There is a distinction between the disbelief of a witness and a conclusion of fabrication.
Likewise, a disbelieved exculpatory statement has no value while a fabricated statement can be used in evidence. The judge should consider the content of the statement and its connection with the charge.
A finding of fabrication cannot be inferred simply on a finding of disbelief. Fabrication must be found "on evidence that is independent from the evidence that contradicts or discredits the accused’s version of events". The circumstance under which the disbelieved evidence was given is not "independent evidence" permitting an adverse inference.
Direct evidence of fabrication however does not need to be confirmed or independently proven.
This evidence includes the circumstances where an accused made a disbelieved out-of-court statement, such that it suggests the accused's intent to mislead or deflect suspicion and shows a conscious knowledge that he committed an offence.
Rejecting Defence Evidence
A considered and reasoned acceptance of the Crown evidence beyond a reasonable doubt on points of conflicting evidence may be sufficient to constitute an explanation to reject defence evidence.
There is a "real danger" that a jury, faced with an argument seeking that they disbelieve the exculpatory explanation of the accused, will infer guilt, especially where the exculpatory version was heard for the first time at trial.
R v Snelson, 2013 BCCA 550 (CanLII), at paras 23 to 32 - no need for instructions on adverse inference on rejected alibi
R v Hibbert, 2002 SCC 39 (CanLII),  2 SCR 445, at paras 57-58
R v Coutts 1998 CanLII 4212 (ON CA), (1998), 126 CCC (3d) 545 (Ont. C.A.), at paras 15-16
R v O’Connor 2002 CanLII 3540 (ON CA), (2002), 62 O.R. (3d) 263 (C.A.), at para 17
R v Nedelcu, 2012 SCC 59 (CanLII) at para 23 ("rejection of an accused's testimony does not create evidence for the Crown")
Snelson, supra at para 27
O'Connor, supra at para 18
R v Cyr, 2012 ONCA 919 (CanLII) at para 78
Cyr, ibid. at para 78
O’Connor, supra, at para 21
Coutts, supra at paras 15-16
O'Connor at para 23 ("...when it is an accused's testimony which is disbelieved, the circumstance in which the accused gave the disbelieved version of events -- as part of the trial process itself -- is not considered to be independent evidence of fabrication permitting an adverse inference against the accused:... Before an adverse inference may be drawn, there must be evidence capable of showing fabrication apart from both the evidence contradicting the accused's testimony and the fact that the accused is found to have testified falsely at the trial.")
- R v Pollock (2004), 2004 CanLII 16082 (ON CA), 188 O.A.C. 37, 187 C.C.C. (3d) 213, per Rosenberg J.A. at para. 155, (“[t]here is no requirement, however, that the evidence of fabrication must itself be confirmed or independently proved.”)
Cyr, supra at para 79
O'Connor, supra at para 24, 26
R v TM, 2014 ONCA 854 (CanLII), 318 C.C.C. (3d) 153, at para. 68
R v JA, 2010 ONCA 491 (CanLII), 261 C.C.C. (3d) 125, at paras. 22-23
R v M, 2017 ONSC 5537 (CanLII), at para 30
R v JS, 2018 ONCA 39 (CanLII) at para 63
R v Oland, 2016 NBCA 58 (CanLII) at para 66 to 69
Factors in Evaluating Credibility and Reliability
There are many tools for assessing the credibility and reliability of a witness' testimony:
- Internal inconsistencies: consider the inconsistencies with previous statements or testimony at trial.
- External inconsistencies: consider the contradictory and corroborative evidence between witnesses;
- Bias and Partiality: assess the partiality of witnesses due to kinship, hostility, self-interest, or any other motive to favour or injure the accused;
- Capacity: consider the capacity of the witness to relate their testimony:
- ability and opportunity to observe,
- ability to remember and
- ability to communicate the details of their testimony;
- Justifiable error: consider whether the witness, because of the turmoil surrounding the event at the time it occurred, have been easily or understandably in error as to detail, or even as to the time of the occurrence;
- consider the emotional state of the witness at the time (in a calm state or panicked state, for example);
- if recollection was recorded, consider the timing at which notes where made;
- consider the demeanor of the witness in the witness box (voice tone, body language, etc)
- consider the manner of response, being whether the witness was forthright and responsive to questions or was the witness evasive, non-responsive, argumentative, or hesitant to answer (either at time of testimony or in prior statements);
- consider whether
- consider whether common sense suggests that the evidence is impossible or highly improbable or whether it was reasonable and consistent with itself and with the uncontradicted facts.
- considering whether a persons' words and actions are explained and whether it matches their emotional state at the time
- the reasonableness of a person's reaction to events
- evidence showing the demeanor of a complainant shortly following the offence can be useful to credibility. A person alleging a sexual assault or common assault may be quite upset when speaking to police, which may lend to credibility.
- whether there is any embellishment or minimizing of events. Likewise, an signs of attempts at recasting evidence to suit a particular goal; putting himself in a good light,
- whether the witness adjusted their evidence when confronted with new evidence or simply gave different explanations for a single action.
- whether the explanation contains an inordinate level of complexity.
e.g. see list in R v Jacquot, 2010 NSPC 13 (CanLII) at para 40
R v Comer, 2006 NSSC 217 (CanLII) at para 96
R v Snow, 2006 ABPC 92 (CanLII) at para 70
R v McKay, 2011 ABPC 82 (CanLII) at para 14
R v Abdirashid, 2012 ABPC 22 (CanLII),  A.J. No 131 at paras 8 to 11
R v Golightly, 2007 Carswell 3198 at para 65
Baker-Warren v. Denault, 2009 NSSC 59 (CanLII) at para 19
Faryna v Chorny,  2 D.L.R. 354 (BCCA) at para 9, 10
R v DFM, 2008 NSSC 312 (CanLII) at para 11 citing R v Ross, 2006 NSPC 20(*no CanLII links) at para 6
e.g. R v McGraph, 2014 NLCA 40 (CanLII) at para 19 citing trial judge's reasons for disbelieving accused ("Her answers to other questions were often vague and evasive. When confronted by evidence that was contrary to her testimony, the accused would immediately recant and change her testimony to conform.")
- A judge is entitled to consider the emotional condition of the accused for consistency with the claimed offence:
R v Murphy, 1976 CanLII 198,  2 SCR 603, Spence J. for the majority at 612.
See also R v Sidhu, 2004 BCCA 59 (CanLII), 183 CCC (3d) 199 at para 51;
R v Lavallee,  BCJ No. 669(*no CanLII links) at paras 2, 5 and 11 (C.A.)
R v Huang,  BCJ No 1296 at 7 (C.A.)(*no CanLII links) per Macdonald J.A.; and
R v Dorsey,  O.J. No. 349(*no CanLII links) at 4-5 (C.A.)
- R v Mete,  O.J. No. 16 (OCJ)(*no CanLII links)
e.g. McGrath, supra at para 19
e.g. McGrath, supra at para 19
Consistencies and inconsistencies are an "important aspect" in assessing credibility.
Generally speaking, inconsistencies in a witnesses evidence must be evaluated before the judge can accept it.
Inconsistencies on peripheral matters and not to the "essence" of the charges and so may be excused.
A series of minor inconsistencies "may become quite significant and cause the trier of fact to have a reasonable doubt about the reliability of the witness's evidence". The trier-of-fact should consider the "totality of the inconsistencies in order to assess whether the witness's evidence is reliable".
The trial judge does not need to address every inconsistency. 
Inconsistencies between witnesses regarding "peripheral matters" such as time, speed and distance, all of which are affected by subjective assessments, will usually have a limited affect on reliability unless glaringly different. Minor differences on details can in fact enhance, rather than detract, from the credibility of the witness as too much similarity will suggest collusion.  Such inconsistencies should be considered in the context of the witnesses age at the time of the events.
Where there are two equally credible witnesses there are a number of rules of thumb that can be applied:
- the testimony must be contrasted with the undisputed facts to see which is the closer "fit".
- The judge should consider what is reasonably recallable and not recallable by the particular witness.
- the judge should favour the witness who is in a better position to know a particular fact.
- where evidence is "incredible", there must be more undisputed facts to support this claim
An inconsistency may or may not be significant depending on whether such errors in detail are "normal" and "to be expected" or, alternatively, are errors that "are "unlikely to be mistaken" and "demonstrate a carelessness with the truth or raise reliability issues".
Where there are major inconsistencies or contradictions with with key crown witnesses, or where there are otherwise conflicting evidence, the trier-of-fact would be "carefully assess" the evidence before.
R v CH, 1999 CanLII 18939 (NL CA), 182 Nfld. & P.E.I.R. 32, 44 W.C.B. (2d) 162 (Nfld. C.A.) at para 23
e.g. R v Wigle, 2009 ONCA 604 (CanLII) - conviction overturned because judge failed to explain why complainant's inconsistencies did not affect credibility.
see also CH, supra at para 23
R v Broesky, 2014 SKCA 36 (CanLII), at para 3
R v Lindsay, 2012 SKCA 33 (CanLII)
CH, supra at para 29
- R v R.S., 2014 NSCA 105 (CanLII) at para 24
R v DLW, 2013 BCSC 1327 (CanLII) at para 129
R v AF 2010 ONSC 5824 (CanLII), at para 87
e.g. DLW, supra at para 128
- R v Tran 1994 CanLII 56 (SCC) at 248
R v FE, BCCA 414 (CanLII), (1999), 126 BCAC 161
R v Ross, 2002 BCSC 445 (CanLII)
- R v U(FJ), 1994 CanLII 1085 (ON C.A.)
- R v B(G), 1990 CanLII 115 (SCC),  2 SCR 57
R v Smith, 2018 ABQB 199 (CanLII) at para 50
R v MG (1994), 1994 CanLII 8733 (ON CA),  OJ No 2086 at para 23, appeal discontinued  SCCA No 390
R v AM, 2014 ONCA 769 (CanLII) at para 12
R v SW, 1994 CanLII 7208 (ON CA), (1994), 18 O.R. (3d) 509 (C.A.), at p. 517
R v Oziel, 1997 CanLII 549 (ON CA),  O.J. No. 1185 (C.A.), at paras 8, 9
R v Norman 1993 CanLII 3387 (ON CA), (1993), 87 CCC (3d) 153 (Ont. C.A.), at pp. 172-4
Consistencies and Corroboration
Motive and Bias
The judge may take into account the existence or absence of evidence of a motive to fabricate the allegation. There is no onus on the accused to establish a motive to lie on the part of the complainant.  Do to otherwise, would have the effect of removing the presumption of innocence.
Motive is only one factor to consider when assessing credibility.
The absence of motive to fabricate should not be given undue weight to suggest that the complainant is telling the truth. Suggesting that it is true unfairly bolster's the witness's credibility. Corrective jury instructions should be given if such a suggestion is made.
Evidence establishing motive is always admissible, but it should not be mistaken for evidence that merely shows a history of incidents between parties. The Crown may present evidence that suggests an absence of any motive on the part of the complainant to fabricate their story.
Proven absence of motive is "always an important fact in favour of the accused".
Where the accused theory alleges that a Crown witness lied out of self-interest, the judge may "consider that the [Crown] witness would have had no, or less, reason to be untruthful on particular points of evidence in respect of which [the accused] provided radically inconsistent testimony".
It is permitted for the trial judge to conclude that the evidence of a witness are not based on actual memories but are more likely rationalizations, assumptions or believed on how they would have behaved.
see R v Jackson, 1995 CanLII 3506 (ON CA),  O.J. No. 2471 (C.A.)
R v LeBrocq, 2011 ONCA 405 (CanLII),  O.J. No. 2323
R v Plews, 2010 ONSC 5653 (CanLII) at para 335
R v KGB, 1993 CanLII 116 (SCC), 79 CCC (3d) 257 (S.C.C.) at p.300
R v Greer, 2009 ONCA 505 (CanLII), at para 5
R v Batte 2000 CanLII 5750 (ON CA), (2000), 49 O.R. (3d) 321 (C.A.) at paras 120-124
R v Krack, (1990), 56 CCC (3d) 555(*no CanLII links) at 561-562 (Ont. CA)
Plews, supra at para 335
Batte, supra at para 120-124
- R v LL, 2009 ONCA 413 (CanLII) at para 40 to 42
- see LL, ibid. at para 53
- R. v Barbour,  SCR 465, 1938 CanLII 29 (SCC) at page 5 per Duff C.J.
- R v AJS, 1998 CanLII 18004 (NL CA)
- R v Lewis,  2 SCR 821, 1979 CanLII 19 (SCC) at pages 12-14 per Dickson, J.
R v Laboucan,  1 SCR 397, 2010 SCC 12 (CanLII), per Charron J, at para 22
R v BJT  SJ No 801 at para 19
R v Chen, 2016 ABQB 644 (CanLII), at para 122
R v JR, 2006 CanLII 22658 (ON SC) at paras 21 to 22
Evidence of emotional state "may constitute circumstantial evidence confirming that the offence occurred... including the temporal nexus to the alleged offence and the existence of alternative explanations for the emotional state." 
A witnesses level of intoxication will tend to reduce the amount of reliability placed upon the witnesses evidence.
Credibility may be assessed from demeanour. This can include "non-verbal cues" and "body language, eyes, tone of voice, and the manner" of speaking  as well as "their movements, glances, hesitations, trembling, blushing, surprise or bravado".
Reliability of Demeanour
However, a subjective view of demeanour can be unreliable indicator of accuracy.
A judge should not decide on credibility on the strength of demeanour evidence as it would be too "dangerous".
The conduct and behaviour of a witness in court should not be given too much weight.
It should be recognized that witnesses are testifying in a foreign environment and are often nervous and are feeling significant pressure, especially when undergoing prolonged cross-examination.
Decision Exclusively on Demeanour
A decision on credibility based solely on demeanour of a witness is an error.
Demeanour evidence alone is not always considered a proper manner of assessing credibility.
Demeanour by itself cannot be sufficient alone to make a conclusion on credibility or conviction, especially where there are "significant and unexplained inconsistencies in the evidence.
- R v N.S. (2010) 102 OR (3d) 161 (CA) at para 55, 57
- Laurentide motels ltd. v Beauport (City), 1989 CanLII 81 (SCC),  1 SCR 705 per L'Heureux-Dube J.
Law Society of Upper Canada v Neinstein, 2010 ONCA 193 (CanLII), 99 O.R. (3d) 1 (C.A.), at para 66
R v Smith, 2010 ONCA 229 (CanLII), at para 11
R v GG 1997 CanLII 1976 (ON CA), (1997), 115 CCC (3d) 1 (Ont. C.A.), at pp. 6-8
R v P.-P.(S.H.) 2003 NSCA 53 (CanLII), (2003), 176 CCC (3d) 281 (NSCA), at paras 28-30
R v Levert 2001 CanLII 8606 (ON CA), (2001), 159 CCC (3d) 71 (Ont. C.A.), at pp. 80-2
- R v JAA, 2011 SCC 17 (CanLII),  1 SCR 628 at para 14 (“it would be dangerous for this Court to uphold the convictions and thus resolve the credibility issue in this case on the strength of demeanour evidence, or on the basis that one party’s version was less plausible than the other’s.”)
R v Jeng, 2004 BCCA 464 (CanLII) at para 54
R v Shields, 2017 BCPC 395 (CanLII) at para 74
R v DTO, 2018 BCPC 120 (CanLII), per MacCarthy PCJ at para 125
e.g. R v JF, 2003 CanLII 52166 (ON CA), (2003), 177 CCC (3d) 1 at para 101
R v Norman 1993 CanLII 3387 (ON CA), (1993), 87 CCC (3d) 153 at 173
R v Gostick 1999 CanLII 3125 (ON CA), (1999), 137 CCC (3d) 53 at 59-61
R v KA, 1999 CanLII 3756 (ON CA), (1999), 137 CCC (3d) 554 (Ont. C.A.), at para 44
R v Penney,  N.J. No. 98 (N.L.C.A.), at para 61
R v Jennings,  N.J. No. 388 (T.D.), at 21
see R v WS, 1994 CanLII 7208 (ON CA), (1994), 90 CCC (3d) 242 (Ont. C.A.) at p. 250
Faryna v Chorny,  2 D.L.R. 354 (BCCA) by O'Halloran J.A. at p. 357 ("The real test of the truth of a story of a witness in such a case must be its harmony with the preponderance of the probabilities which a practical and informed person would readily recognize as reasonable in that place in those conditions")
There is some support for the proposition that judge may rely upon their intuition to determine the credibility of a witness. A judge will often invoke their appreciation that the witness has a "ring of truth".
Common Sense and Plausibility
It would be dangerous to uphold a conviction "on the basis that one party's version was less plausible than the other's" alone. That is not to say that common sense and plausibility are not useful tools in evaluating evidence. Triers-of-fact are permitted to reject a witnesses evidence, including that of the accused, on the basis that it does not accord with "collective human understanding of the behaviour" of a person in the shoes of the alleged victim.
It is said that "[h]uman nature, common sense and life's experience are indispensable when assessing credibility".
- R v JAA, 2011 SCC 17 (CanLII),  1 SCR 628 at para 14 (“it would be dangerous for this Court to uphold the convictions and thus resolve the credibility issue in this case on the strength of demeanour evidence, or on the basis that one party’s version was less plausible than the other’s.”)
R v Kontzamanis, 2011 BCCA 184 (CanLII) at para 38
R v DDS, 2006 NSCA 34 (CanLII) per Saunder JA
Observations Made in Court
A judge should not reject the defence evidence based solely on observations of the witness' build to infer his capacity.
- R v Gyimah, 2010 ONSC 4055 (CanLII), judge wrongly rejected defence evidence of difficulty in moving a mattress because the accused "looked fit"
Evidence of Collusion or Tainting
Evidence that the witness was influenced by others would be reason to give no weight to their evidence.
There is no requirement that the judge must make an actual finding that collusion occurred in order to discount the evidence of a witness. In some circumstances it is open to the judge to rely upon an "opportunity to collude". However, a witness should generally not be entirely discredited merely on the basis of opportunity.
Collusion can be unintentional such as where multiple individuals watch the same news story and are influenced by the single story.
Tainting of Evidence
The independence of a person's recollection can be compromised by being exposed to other persons statements.
A witness who sat in on the preliminary inquiry evidence before giving a statement to police can be reason to find there is no credibility in their evidence.
R v Shearing,  3 SCR 33, 2002 SCC 58 (CanLII)
R v Burke, 1996 CanLII 229 (SCC),  1 S.C.R. 474 at para 45
e.g. Almasi, 2016 ONSC 2943 (CanLII), at paras 47 to 51 - witness evidnece incorrectly dismissed simply because it matched another witness believed to be lying
R v Dorsey, 2012 ONCA 185 (CanLII) per MacPherson JA.
Eg. R v Burton, 2017 NSSC 3 (CanLII), per Arnold J, at para 40
e.g. R v Corbett, 2015 ONSC 1633 (CanLII), per Hambly SCJ, at para 10
Special Types of Testimony
Judge's must be very careful to avoid falling into an analysis which compares the two versions without assessing "the whole evidence to establish proof of guilt beyond a reasonable doubt."
The trier of fact should not place much weight on exculpatory stories in absence of evidence supporting the theory.
There are special considerations when assessing credibility no a Charter voir dire.
No Presumptions for Truthfulness or Accuracy
There is no legal presumption that those testifying in criminal trials are telling the truth or that they are testifying accurately.
- R v Ogden, 2011 NSCA 89 (CanLII) at para 10
R v WH 2011 NLCA 59 (CanLII)
- R v Jenner 2005 MBCA 44 (CanLII), (2005), 195 CCC (3d) at para 21
R v Costache, 2013 ONSC 4447 (CanLII) at para 34
- Costache at para 34
See: R v Gunsch, 2013 ABPC 104 (CanLII) at paras 27 ‑ 37
R v Luciano, 2011 ONCA 89 (CanLII)
R v Thain, 2009 ONCA 223 (CanLII), at para 32
R v Downey, 2013 NSCA 101 (CanLII) at paras 15-20
Credibility of Accused (The W.D. Test)
The WD Test which concerns analysis of the accused testifying, has application outside of merely the accused testifying but also on any evidence called by the defence that conflicts with the Crown evidence on a "vital" issue.
Assessing An Accused Cautioned Statement to Police
Where the Crown adduces the accused's statement to police as part of it case, the Court must assess that evidence which addresses a "vital issue" in the same manner as if the accused testified himself.
R v M, 2017 ONSC 5537 (CanLII) at para 29 at para 29 ("The W.(D.) analysis applies where, on a vital issue, there are credibility findings to be made between conflicting evidence called by the defence or arising out of evidence favourable to the defence in the Crown’s case.")
R v BD, 2011 ONCA 51 (CanLII), at para 114 ("What I take from a review of all of these authorities is that the principles underlying W.(D.) are not confined merely to cases where an accused testifies and his or her evidence conflicts with that of Crown witnesses. They have a broader sweep. Where, on a vital issue, there are credibility findings to be made between conflicting evidence called by the defence or arising out of evidence favourable to the defence in the Crown’s case, the trial judge must relate the concept of reasonable doubt to those credibility findings.")
R v Morningstar, 2017 NBCA 39 (CanLII)
R v Castelein and Berthelette, 2017 MBQB 173 (CanLII), at para 13 ("In deciding whether the Crown has met its burden, I must consider Mr. Berthelette’s exculpatory statement in the same manner as I would had he testified")
R v BD, 2011 ONCA 51 (CanLII), at para 114 ("What I take from a review of all of these authorities is that the principles underlying W.(D.) are not confined merely to cases where an accused testifies and his or her evidence conflicts with that of Crown witnesses. They have a broader sweep. Where, on a vital issue, there are credibility findings to be made between conflicting evidence called by the defence or arising out of evidence favourable to the defence in the Crown’s case, the trial judge must relate the concept of reasonable doubt to those credibility findings. ")
Credibility of Persons from Other Cultures
Assessing Interpreter Evidence
Assessing credibility through an interpreter requires careful consideration as it is recognized as a much more difficult endeavour.
Courts should not put too much weight on perceived inconsistencies where evidence is conveyed through a interpreter.
Sopinka, Lederman & Bryant, The Law of Evidence in Canada (2nd ed.) (Toronto: Butterworths, 1999), at s. 16.25
R v Singh, 2016 ONSC 3688 (CanLII)
R v Tran, 1994 CanLII 56 (SCC),  2 SCR 951, at p. 248 (court suggests that testifying through interpreter should have “benefit of the doubt” with respect to inconsistencies)
R v X(J), 2012 ABCA 69 (CanLII), at para. 13 ("Some confusion …[is] inevitable" and can result in a record that is “is often unclear”)
R v Zewari, 2005 CanLII 16078 (ON CA),  O.J. No. 1953 (C.A.), at para. 4 (trial judge properly averted to difficulty in evaluating credibility when an interpreter is required)
Serrurier v. City of Ottawa (1983), 1983 CanLII 1628 (ON CA), 42 O.R. (2d) 321 (C.A.), at pp. 322-23 (“Cross examination becomes more difficult, and often less effective, when each question and answer must be interpreted”)
J.H. Wigmore, Evidence in Trials at Common Law (Chadbourn Rev.) (Toronto: Little Brown and Co., 1979), Vol. 3, §811 (quoting: “ARTHUR TRAIN, The Prisoner at the Bar 239 (1908) … It is also practically impossible to cross examine through an interpreter, for the whole psychological significance of the answer is destroyed, ample opportunity being given for the witness to collect his wits and carefully to frame his reply”)
Tran, supra at p. 987 ("the courts have cautioned that interpreted evidence should not be examined microscopically for inconsistencies. The benefit of a doubt should be given to the witness")
R v JX, 2012 ABCA 69 (CanLII) at para 13
R v Zewari, 2005 CanLII 16078 (ON CA),  O.J. No. 1953 (C.A.)(QL), at para 4
NAFF v Minister of Immigration (2004), 221 C.L.R. 1 (H.C. Aust.), at para 30
Sopinka, Lederman & Bryant, The Law of Evidence in Canada (2nd ed.) (Toronto: Butterworths, 1999), at s. 16.25 ("It is much more difficult to assess the credibility of evidence given through an interpreter")
Credibility of Children
Adults Testifying to Events Occurring When a Child
Adults testifying to events that occurred while they were a child should be assessed using standard factors for adult witnesses. However, the evidence should be considered in the context of the age of the witness. Minor inconsistencies should be considered in light of the witnesses age at the time.
Common sense should be applied to the level of "exactitude and detail" which may be missing from a child's world perspective.
Credibility of Police Officers
It is not proper for courts to take the evidence of a police officer over that of a civilian by virtue of their position.
Police notes are no longer simply an aide-memoire simply used to refresh an officer's memory. Officers have an "inherent duty" to take notes.
Without notes an officer's credibility can be diminished and his evidence can be discounted.
Police notes must be independent and contemporaneous.  This is essential to the reliability and integrity of the officer's notes. Notes are only for the purpose of assisting the officer in testifying at trial. Without notes the evidence of the officer can be "sketchy at best" and will be unreliable. There must be indication that the notes are the officer's independent recollection. An officer should not be using someone else's notes to refresh their memory or else they will simply be reciting hearsay.
As a general rule in an investigation involving multiple officers, notes should not be made after a collective debriefing.
The absence of note taking can go to the reliability of the officer's testimony. Where an officer is experienced they should be in the practice of taking notes of all relevant observations.
An officer is expected to take notes of all significant aspects of their investigation. Proper note taking is an important part of the fact-finding, as evidence should not be left to the whim of memory.
It is not an acceptable excuse to not have notes where the officer “would remember it”. Where notes are not taken the court is allowed to conclude that observation evidence was in fact not observed but a belief created after the investigation. This is not necessarily always the case however and the judge may still accept the evidence.
Memory of a police officer for things that occurred a considerably long time in the past where no notes were taken will has diminished reliability.
The effect of an absence of notes will vary from case-to-case.
Failure to take proper notes on observations of impairment allows a judge to find that there were insufficient evidence to form reasonable and probable grounds.
R v Odgers, http://canlii.ca/t/24407 2009 ONCJ 287] (CanLII),  O.J. No. 2592 at para 16
Odgers, ibid. at para 16
Schaeffer v Wood, 2011 ONCA 716 (CanLII), (2011), 107 O.R. (3d) 721 at paras 69-70 on appeal to SCC
- Schaeffer v Wood, ibid.
- Schaeffer v Wood, ibid.
- Schaeffer v Wood, ibid.
- R v Thompson,  O.J. No. 1236 (Sup. Ct.) at para 212 ("[W]here multiple officers participate in investigation of an incident, their notes should be made independently and not as a collective and not after a (de)briefing where the incident is discussed as a group.")
R v Tang, 2011 ONCJ 525 (CanLII)at para 53 -- police officer evidence entirely ignored due to poor notes
R v Odgers, 2009 ONCJ 287 (CanLII)
R v Machado, 2010 ONSC 277 (CanLII) at 120-123
- R v Lozanovski, 2005 ONCJ 112 (CanLII),  O.C.J. 112 at p.3
- R v Zack 1999 OJ No 5747 (ONCJ) at p.2
R v Khan, 2006 OJ 2717 at 18
- R v Zack at p. 2
- e.g. R v Thompson, 2001 CanLII 24186 (ON CA)
R v Bennett, 2005 OJ No 4035 ONCJ)
- Khan (2006), O.J. 2717 at paras 17 to 18
R v Hayes, 2005 OJ No 5057 at 9
R v McGee, 2012 ONCJ 63 (CanLII) at para 66
R v Noureddine,  O.J. No. 1397 (OCJ) at paras 12 to 17
- R v Bero, 2014 ONCJ 444 (CanLII)
Credibility of the Complainant or Victim
Credibility for Other Types of Witnesses
Expert evidence may be admitted to establish the effect that the "code of silence" will have upon a witness including a reluctance to testify or a prior inconsistent statement.
- e.g. R v Boswell, 2011 ONCA 283 (CanLII)