Qualified Expert Evidence: Difference between revisions

From Criminal Law Notebook
m Text replacement - "<Br>" to "<br>"
m Text replacement - "(R v [A-Z][a-z]+)," to "''$1'',"
Line 6: Line 6:
Folkes v Chadd (1782), 3 Dougl. 157<br>
Folkes v Chadd (1782), 3 Dougl. 157<br>
R v J-L J, [2000] 2 SCR 600, [http://canlii.ca/t/5246 2000 SCC 51] (CanLII){{perSCC|Binnie J}} at para 56<br>
R v J-L J, [2000] 2 SCR 600, [http://canlii.ca/t/5246 2000 SCC 51] (CanLII){{perSCC|Binnie J}} at para 56<br>
R v Abbey, [http://canlii.ca/t/1lpcd 1982 CanLII 25] (SCC), [1982] 2 SCR 24{{perSCC|Dickson J}}<br>
''R v Abbey'', [http://canlii.ca/t/1lpcd 1982 CanLII 25] (SCC), [1982] 2 SCR 24{{perSCC|Dickson J}}<br>
R v Mohan [http://canlii.ca/t/1frt1 1994 CanLII 80] (SCC), [1994] 2 SCR 9{{perSCC|Sopinka J}} at 413 (the opinion must "provide information ‘which is likely to be outside the experience or knowledge of’” the trier of fact")<br>
R v Mohan [http://canlii.ca/t/1frt1 1994 CanLII 80] (SCC), [1994] 2 SCR 9{{perSCC|Sopinka J}} at 413 (the opinion must "provide information ‘which is likely to be outside the experience or knowledge of’” the trier of fact")<br>
''R v Bunniss'' (1964), 44 CR 262 (BC Co. Ct.), [http://canlii.ca/t/gcwck 1964 CanLII 673] (BC SC){{perBCSC|Tyrwhitt-Drake J}} (an expert is "one who has by dint of training and practice, acquired a good knowledge of the science or art concerning which his opinion is sought, and the practical ability to use his judgment in that science")<br>
''R v Bunniss'' (1964), 44 CR 262 (BC Co. Ct.), [http://canlii.ca/t/gcwck 1964 CanLII 673] (BC SC){{perBCSC|Tyrwhitt-Drake J}} (an expert is "one who has by dint of training and practice, acquired a good knowledge of the science or art concerning which his opinion is sought, and the practical ability to use his judgment in that science")<br>
Line 12: Line 12:
The expert must have special knowledge in the matter
The expert must have special knowledge in the matter
<ref>  
<ref>  
R v Terceira, [http://canlii.ca/t/6gmx 1998 CanLII 2174] (ON CA), (1998) 123 CCC 1 (Ont. CA){{perONCA|Finlayson JA}}
''R v Terceira'', [http://canlii.ca/t/6gmx 1998 CanLII 2174] (ON CA), (1998) 123 CCC 1 (Ont. CA){{perONCA|Finlayson JA}}
{{supra1|Mohan}} at p. 414 (the witness must be “shown to have acquired special or peculiar knowledge through study or experience in respect of the matters on which he or she undertakes to testify”)
{{supra1|Mohan}} at p. 414 (the witness must be “shown to have acquired special or peculiar knowledge through study or experience in respect of the matters on which he or she undertakes to testify”)
</ref>
</ref>
Line 18: Line 18:
<ref>
<ref>
{{supra1|Mohan}}<br>
{{supra1|Mohan}}<br>
R v Lovie, [http://canlii.ca/t/6jjw 1995 CanLII 801] (ON CA){{perONCA|Finlayson JA}}<br>
''R v Lovie'', [http://canlii.ca/t/6jjw 1995 CanLII 801] (ON CA){{perONCA|Finlayson JA}}<br>
</ref> There must also be no exclusionary rules that would otherwise prohibit the evidence from being given. <ref>
</ref> There must also be no exclusionary rules that would otherwise prohibit the evidence from being given. <ref>
''R v NO'', [http://canlii.ca/t/22ms4 2009 ABCA 75] (CanLII){{TheCourt}} at para 19<br>
''R v NO'', [http://canlii.ca/t/22ms4 2009 ABCA 75] (CanLII){{TheCourt}} at para 19<br>
Line 24: Line 24:


A person testifying to specialized knowledge will not necessarily be required to be qualified as an expert. Where they testify to their "factual knowledge" based on their "knowledge, observations and experience".<ref>
A person testifying to specialized knowledge will not necessarily be required to be qualified as an expert. Where they testify to their "factual knowledge" based on their "knowledge, observations and experience".<ref>
R v Hamilton, [http://canlii.ca/t/fljvz 2011 ONCA 399] (CanLII){{TheCourt}} at paras 273 to 284 - evidence from phone company as to the mechanical workings of cell towers and their relationship to the cell phone<br>
''R v Hamilton'', [http://canlii.ca/t/fljvz 2011 ONCA 399] (CanLII){{TheCourt}} at paras 273 to 284 - evidence from phone company as to the mechanical workings of cell towers and their relationship to the cell phone<br>
R v Ranger, [http://canlii.ca/t/2db2k 2010 ONCA 759] (CanLII){{TheCourt}} -- cell phone tower evidence<br>
''R v Ranger'', [http://canlii.ca/t/2db2k 2010 ONCA 759] (CanLII){{TheCourt}} -- cell phone tower evidence<br>
c.f. R v Korski, [http://canlii.ca/t/236fj 2009 MBCA 37] (CanLII){{perSCC|Steel JA}} -- required expert to testify on cell tower evidence<br>
c.f. ''R v Korski'', [http://canlii.ca/t/236fj 2009 MBCA 37] (CanLII){{perSCC|Steel JA}} -- required expert to testify on cell tower evidence<br>
</ref>
</ref>


Line 35: Line 35:
The expert is not to testify to facts, but rather only opinion to allow the trier-of-fact to draw inferences.
The expert is not to testify to facts, but rather only opinion to allow the trier-of-fact to draw inferences.
<ref>
<ref>
R v Parrott,  [http://canlii.ca/t/523h 2001 SCC 3] (CanLII), [2001] 1 SCR 178{{perSCC|Binnie J}}<br>
''R v Parrott'',  [http://canlii.ca/t/523h 2001 SCC 3] (CanLII), [2001] 1 SCR 178{{perSCC|Binnie J}}<br>
R v Lavallee, [http://canlii.ca/t/1fsx3 1990 CanLII 95] (SCC), [1990] 1 SCR 852{{perSCC|Wilson J}}
''R v Lavallee'', [http://canlii.ca/t/1fsx3 1990 CanLII 95] (SCC), [1990] 1 SCR 852{{perSCC|Wilson J}}
</ref>  
</ref>  


Line 47: Line 47:
The key requirement for expert evidence is that the expert "possesses special knowledge and experience going beyond that of the trier of fact".<ref>
The key requirement for expert evidence is that the expert "possesses special knowledge and experience going beyond that of the trier of fact".<ref>
R v Béland, [http://canlii.ca/t/1ftm1 1987 CanLII 27] (SCC), [1987] 2 SCR 398{{perSCC|McIntyre J}} at p. 415<br>
R v Béland, [http://canlii.ca/t/1ftm1 1987 CanLII 27] (SCC), [1987] 2 SCR 398{{perSCC|McIntyre J}} at p. 415<br>
R v Marquard, [http://canlii.ca/t/1frx2 1993 CanLII 37] (SCC), [1993] 4 SCR 223{{perSCC|McLachlin J}} at para 35<br>
''R v Marquard'', [http://canlii.ca/t/1frx2 1993 CanLII 37] (SCC), [1993] 4 SCR 223{{perSCC|McLachlin J}} at para 35<br>
R v Chan, [http://canlii.ca/t/2d9sb 1993 ABCA 383] (CanLII), (1993), 145 A.R. 304{{TheCourtABCA}} at para 9<br>
''R v Chan'', [http://canlii.ca/t/2d9sb 1993 ABCA 383] (CanLII), (1993), 145 A.R. 304{{TheCourtABCA}} at para 9<br>
</ref>
</ref>
As long as the court is satisfied that the witness is sufficiently experienced he should be qualified.<ref>
As long as the court is satisfied that the witness is sufficiently experienced he should be qualified.<ref>
Line 59: Line 59:
The means by which the skill, expertise, or knowledge was acquired goes to weight and not admissibility.<ref>
The means by which the skill, expertise, or knowledge was acquired goes to weight and not admissibility.<ref>
Chan at para 9 citing Sopinka, Lederman and Bryant, The Law of Evidence of Canada (1992), at pp. 536‑537: ("As long as the court is satisfied that the witness is sufficiently experienced in the subject matter at issue, the court will not be concerned with whether his or her skill was derived from specific studies or by practical training, although that may affect the weight to be given to the evidence.")
Chan at para 9 citing Sopinka, Lederman and Bryant, The Law of Evidence of Canada (1992), at pp. 536‑537: ("As long as the court is satisfied that the witness is sufficiently experienced in the subject matter at issue, the court will not be concerned with whether his or her skill was derived from specific studies or by practical training, although that may affect the weight to be given to the evidence.")
R v Rayner, [http://canlii.ca/t/4v87 2000 NSCA 143] (CanLII), 189 N.S.R. (2d) 144{{perNSCA|Saunders JA}}
''R v Rayner'', [http://canlii.ca/t/4v87 2000 NSCA 143] (CanLII), 189 N.S.R. (2d) 144{{perNSCA|Saunders JA}}
</ref>
</ref>
It is acceptable to obtain the ability to give an opinion from study, instruction, practical experience or observations. Formal study in not necessary.<ref>
It is acceptable to obtain the ability to give an opinion from study, instruction, practical experience or observations. Formal study in not necessary.<ref>
R v Melaragni, (1992), 73 CCC (3d) 348 (Ont. Ct. Gen. Div.), [http://canlii.ca/t/gcw35 1992 CanLII 12764] (ON SC){{perONCA|Moldaver JA}}<br>
''R v Melaragni'', (1992), 73 CCC (3d) 348 (Ont. Ct. Gen. Div.), [http://canlii.ca/t/gcw35 1992 CanLII 12764] (ON SC){{perONCA|Moldaver JA}}<br>
''R v NO'', [http://canlii.ca/t/22ms4 2009 ABCA 75] (CanLII){{TheCourtABCA}} at para 22<br>
''R v NO'', [http://canlii.ca/t/22ms4 2009 ABCA 75] (CanLII){{TheCourtABCA}} at para 22<br>
</ref>
</ref>
Line 92: Line 92:
'''Jury Instruction'''<br>
'''Jury Instruction'''<br>
Wher qualified expert gives opinion evidence outside of their field, the problem can generally be remedied through a "remedial instruction advising the jury to disabuse their minds of the inadmissible evidence".<ref>
Wher qualified expert gives opinion evidence outside of their field, the problem can generally be remedied through a "remedial instruction advising the jury to disabuse their minds of the inadmissible evidence".<ref>
R v Sekhon, 2014 SCC 15 (CanLII){{LinkNeeded}}{{perSCC|Moldaver J}} at para 48<br>
''R v Sekhon'', 2014 SCC 15 (CanLII){{LinkNeeded}}{{perSCC|Moldaver J}} at para 48<br>
</ref>
</ref>


'''Standard of Review'''<br>
'''Standard of Review'''<br>
Trial judges are entitled to "wide discretion" and deference when weighing the costs and benefits of admitting expert evidence.<ref>
Trial judges are entitled to "wide discretion" and deference when weighing the costs and benefits of admitting expert evidence.<ref>
R v Clark, [http://canlii.ca/t/gnqq1 2016 ABCA 72] (CanLII){{TheCourt}}, at para 59 to 62<br>
''R v Clark'', [http://canlii.ca/t/gnqq1 2016 ABCA 72] (CanLII){{TheCourt}}, at para 59 to 62<br>
''R v DD'', [http://canlii.ca/t/525r 2000 SCC 43] (CanLII){{perSCC|Major J}} at para 13<br>
''R v DD'', [http://canlii.ca/t/525r 2000 SCC 43] (CanLII){{perSCC|Major J}} at para 13<br>
R v Soni, [http://canlii.ca/t/gsqz9 2016 ABCA 231] (CanLII){{TheCourt}} (2:1) at para 8<br>
''R v Soni'', [http://canlii.ca/t/gsqz9 2016 ABCA 231] (CanLII){{TheCourt}} (2:1) at para 8<br>
R v Dominic, [http://canlii.ca/t/gpltp 2016 ABCA 114] (CanLII){{TheCourt}} at para 17<br>
''R v Dominic'', [http://canlii.ca/t/gpltp 2016 ABCA 114] (CanLII){{TheCourt}} at para 17<br>
R v Abbey, [http://canlii.ca/t/259rl 2009 ONCA 624] (CanLII){{perONCA|Doherty JA}} at para 97, leave to appeal to SCC refused<br>
''R v Abbey'', [http://canlii.ca/t/259rl 2009 ONCA 624] (CanLII){{perONCA|Doherty JA}} at para 97, leave to appeal to SCC refused<br>
</ref>
</ref>


Line 120: Line 120:
The expert must cite the bases on his opinion in order for the trier-of-fact to evaluate the opinion.
The expert must cite the bases on his opinion in order for the trier-of-fact to evaluate the opinion.
<ref>
<ref>
R v Neil, [http://canlii.ca/t/22tpj 1957 CanLII 70] (SCC), [1957] SCR 685{{Plurality}}<br>
''R v Neil'', [http://canlii.ca/t/22tpj 1957 CanLII 70] (SCC), [1957] SCR 685{{Plurality}}<br>
R v Grandinetti, [http://canlii.ca/t/4pvr 2003 ABCA 307] (CanLII){{perABCA|McFadyen JA}} (2:1)<br>
''R v Grandinetti'', [http://canlii.ca/t/4pvr 2003 ABCA 307] (CanLII){{perABCA|McFadyen JA}} (2:1)<br>
R v Trudel, [http://canlii.ca/t/1p9ln 1994 CanLII 5397] (QC CA){{perQCCA|Brossard JA}}<br>
''R v Trudel'', [http://canlii.ca/t/1p9ln 1994 CanLII 5397] (QC CA){{perQCCA|Brossard JA}}<br>
</ref> The expert can use sources and information found in the "scope of his or her expertise"<ref>
</ref> The expert can use sources and information found in the "scope of his or her expertise"<ref>
''R v SAB'', [http://canlii.ca/t/1g3m0 2003 SCC 60] (CanLII), [2003] 2 SCR 678{{perSCC|Arbour J}} at para 63</ref> as well as sources outside his knowledge in limited contexts.<ref>
''R v SAB'', [http://canlii.ca/t/1g3m0 2003 SCC 60] (CanLII), [2003] 2 SCR 678{{perSCC|Arbour J}} at para 63</ref> as well as sources outside his knowledge in limited contexts.<ref>
''R v Anderson'' (1914), 22 CCC 455, [http://canlii.ca/t/gcgg2 1914 CanLII 361] (AB CA){{perABCA|Harvey J}}<br>
''R v Anderson'' (1914), 22 CCC 455, [http://canlii.ca/t/gcgg2 1914 CanLII 361] (AB CA){{perABCA|Harvey J}}<br>
R v Godfrey, [http://canlii.ca/t/fp05t 1974 ALTASCAD 43] (CanLII), [1974] 4 W.W.R. 677, 18 CCC (2d) 90 (Alta. C.A.){{Plurality}} (2:1), at pp. 102-104
''R v Godfrey'', [http://canlii.ca/t/fp05t 1974 ALTASCAD 43] (CanLII), [1974] 4 W.W.R. 677, 18 CCC (2d) 90 (Alta. C.A.){{Plurality}} (2:1), at pp. 102-104
</ref>  The "second hand" evidence of texts is not admissible as evidence, but can be used to show the information on which the opinion is based.<ref>R v Burns, [http://canlii.ca/t/1frvk 1994 CanLII 127] (SCC), [1994] 1 SCR 656{{perSCC|McLachlin J}}</ref>
</ref>  The "second hand" evidence of texts is not admissible as evidence, but can be used to show the information on which the opinion is based.<ref>''R v Burns'', [http://canlii.ca/t/1frvk 1994 CanLII 127] (SCC), [1994] 1 SCR 656{{perSCC|McLachlin J}}</ref>


An expert may be cross-examined on a text, report or article relating to his area of expertise.
An expert may be cross-examined on a text, report or article relating to his area of expertise.
<ref>
<ref>
R c Taillefer, [http://canlii.ca/t/1nk5h 1995 CanLII 4592] (QCCA){{perQCCA|Proulx JA}}<br>
R c Taillefer, [http://canlii.ca/t/1nk5h 1995 CanLII 4592] (QCCA){{perQCCA|Proulx JA}}<br>
R v Marquard, [http://canlii.ca/t/1frx2 1993 CanLII 37] (SCC), [1993] 4 SCR 223{{perSCC|McLachlin J}}<br>
''R v Marquard'', [http://canlii.ca/t/1frx2 1993 CanLII 37] (SCC), [1993] 4 SCR 223{{perSCC|McLachlin J}}<br>
</ref> The expert can only comment on works they are familiar with. If the expert acknowledges the authority, the examiner may read parts of the document to the witness to the extent that it is accepted as valid. Those confirmed passages will become evidence in the case<ref>
</ref> The expert can only comment on works they are familiar with. If the expert acknowledges the authority, the examiner may read parts of the document to the witness to the extent that it is accepted as valid. Those confirmed passages will become evidence in the case<ref>
Marquard{{ibid}} ("...in examining an expert witness on other expert opinions found in papers or books is to ask the witness if he or she knows the work.  If the answer is "no", or if the witness denies the work's authority, that is the end of the matter.  ...If the answer is "yes", and the witness acknowledges the work's authority, then the witness has confirmed it by the witness's own testimony. Parts of it may be read to the witness, and to the extent they are confirmed, they become evidence in the case.")<br>
Marquard{{ibid}} ("...in examining an expert witness on other expert opinions found in papers or books is to ask the witness if he or she knows the work.  If the answer is "no", or if the witness denies the work's authority, that is the end of the matter.  ...If the answer is "yes", and the witness acknowledges the work's authority, then the witness has confirmed it by the witness's own testimony. Parts of it may be read to the witness, and to the extent they are confirmed, they become evidence in the case.")<br>
Line 139: Line 139:
A judge may reject the uncontradicted expert evidence as unreasonable.
A judge may reject the uncontradicted expert evidence as unreasonable.
<ref>
<ref>
R v Prince, (1971), 6 CCC (2d) 183 (Ont. C.A.), [http://canlii.ca/t/htwr4 1971 CanLII 1285] (ON CA){{perONCA|Gale CJ}}<br>
''R v Prince'', (1971), 6 CCC (2d) 183 (Ont. C.A.), [http://canlii.ca/t/htwr4 1971 CanLII 1285] (ON CA){{perONCA|Gale CJ}}<br>
R v Lambkin, [http://canlii.ca/t/5f67 2002 MBCA 157] (CanLII){{perMBCA|Monnin JA}}<br>
''R v Lambkin'', [http://canlii.ca/t/5f67 2002 MBCA 157] (CanLII){{perMBCA|Monnin JA}}<br>
</ref>
</ref>
The evidence should not be rejected if there is no contradictory evidence and the opinion is not seriously challenged.<ref>R v Molodowic, [http://canlii.ca/t/5262 2000 SCC 16] (CanLII), [2000] 1 SCR 420{{perSCC|Arbour J}}</ref>
The evidence should not be rejected if there is no contradictory evidence and the opinion is not seriously challenged.<ref>''R v Molodowic'', [http://canlii.ca/t/5262 2000 SCC 16] (CanLII), [2000] 1 SCR 420{{perSCC|Arbour J}}</ref>


The expert cannot recite statistical evidence of probabilities based on prior similar events to infer what likely occurred in the incident at issue.<ref>
The expert cannot recite statistical evidence of probabilities based on prior similar events to infer what likely occurred in the incident at issue.<ref>
''R v Klymchuk'' (2005), [http://canlii.ca/t/1m3d6 2005 CanLII 44167] (ON CA), 203 CCC (3d) 341 (Ont. C.A.){{perONCA|Doherty JA}}, at para. 46.
''R v Klymchuk'' (2005), [http://canlii.ca/t/1m3d6 2005 CanLII 44167] (ON CA), 203 CCC (3d) 341 (Ont. C.A.){{perONCA|Doherty JA}}, at para. 46.
R v Shafia, [http://canlii.ca/t/gvdw4 2016 ONCA 812] (CanLII){{perONCA|Watt JA}}{{At|242}} ("An expert is not entitled to give statistical evidence of probabilities based on prior similar events to support a conclusion about what happened on the occasion that forms the subject-matter of charges")<br>
''R v Shafia'', [http://canlii.ca/t/gvdw4 2016 ONCA 812] (CanLII){{perONCA|Watt JA}}{{At|242}} ("An expert is not entitled to give statistical evidence of probabilities based on prior similar events to support a conclusion about what happened on the occasion that forms the subject-matter of charges")<br>
</ref>
</ref>


Line 156: Line 156:
'''Area of Expertise'''<br>
'''Area of Expertise'''<br>
The qualified "area of expertise" does not need to articulate the exact subject matter to which they will give evidence. It often sufficient to articulate the general area of knowledge.<ref>
The qualified "area of expertise" does not need to articulate the exact subject matter to which they will give evidence. It often sufficient to articulate the general area of knowledge.<ref>
e.g. R v Rothgordt, [http://canlii.ca/t/h494z 2017 BCCA 230] (CanLII){{perBCCA|Frankel JA}}{{at|16}}<br></ref>
e.g. ''R v Rothgordt'', [http://canlii.ca/t/h494z 2017 BCCA 230] (CanLII){{perBCCA|Frankel JA}}{{at|16}}<br></ref>


'''Use of Report'''<br>
'''Use of Report'''<br>
It is common-place that an expert may testify with their reports on hand and may refer to them during testimony.<ref>
It is common-place that an expert may testify with their reports on hand and may refer to them during testimony.<ref>
R v Sandham, [2009] OJ No 4517 (Ont. S.C.J.), [http://canlii.ca/t/26cvj 2009 CanLII 58982] (ON SC){{perONSC|Heeney J}} ("Experts are routinely permitted to have their reports in front of them as they testify, and to refer to them as they deliver their evidence. Such reports are frequently entered as exhibits.")<br>
''R v Sandham'', [2009] OJ No 4517 (Ont. S.C.J.), [http://canlii.ca/t/26cvj 2009 CanLII 58982] (ON SC){{perONSC|Heeney J}} ("Experts are routinely permitted to have their reports in front of them as they testify, and to refer to them as they deliver their evidence. Such reports are frequently entered as exhibits.")<br>
</ref>
</ref>


Line 170: Line 170:
===Weight of Opinion===
===Weight of Opinion===
Expert opinion on anything that is not necessary for the trier-of-fact to make findings is not admissible.<ref>
Expert opinion on anything that is not necessary for the trier-of-fact to make findings is not admissible.<ref>
R v Howard, [http://canlii.ca/t/1ft53 1989 CanLII 99] (SCC), [1989] 1 SCR 1337{{perSCC|Lamer J}}<br>
''R v Howard'', [http://canlii.ca/t/1ft53 1989 CanLII 99] (SCC), [1989] 1 SCR 1337{{perSCC|Lamer J}}<br>
R v Béland, [http://canlii.ca/t/1ftm1 1987 CanLII 27] (SCC), [1987] 2 SCR 398{{perSCC|McIntyre J}}
R v Béland, [http://canlii.ca/t/1ftm1 1987 CanLII 27] (SCC), [1987] 2 SCR 398{{perSCC|McIntyre J}}
R v Millar, (1989), 49 CCC (3d) 193 (ONCA), [http://canlii.ca/t/gb34s 1989 CanLII 7151] (ON CA){{perONCA|Morden JA}}, at 220<br>
''R v Millar'', (1989), 49 CCC (3d) 193 (ONCA), [http://canlii.ca/t/gb34s 1989 CanLII 7151] (ON CA){{perONCA|Morden JA}}, at 220<br>
</ref>
</ref>


Line 185: Line 185:


A jury must be instructed that the hearsay evidence of the facts underlying the experts opinion is not admissible for any purpose other than to evaluate the weight of the opinion.<ref>
A jury must be instructed that the hearsay evidence of the facts underlying the experts opinion is not admissible for any purpose other than to evaluate the weight of the opinion.<ref>
R v Babcock, [http://canlii.ca/t/2dgrk 1984 ABCA 291] (CanLII){{perABCA|Moir JA}}
''R v Babcock'', [http://canlii.ca/t/2dgrk 1984 ABCA 291] (CanLII){{perABCA|Moir JA}}
</ref>
</ref>


The weight given to an opinion is a question of fact.<ref>
The weight given to an opinion is a question of fact.<ref>
R v Smithers, [http://canlii.ca/t/1mk9r 1977 CanLII 7] (SCC), [1978] 1 SCR 506{{perSCC|Dickson J}}
''R v Smithers'', [http://canlii.ca/t/1mk9r 1977 CanLII 7] (SCC), [1978] 1 SCR 506{{perSCC|Dickson J}}
</ref>
</ref>


The opinion must be specific to the case and not simply in generalities.<ref>
The opinion must be specific to the case and not simply in generalities.<ref>
R v Li, [http://canlii.ca/t/23m2k 1980 CanLII 344] (BC SC){{perBCSC|Trainor J}}
''R v Li'', [http://canlii.ca/t/23m2k 1980 CanLII 344] (BC SC){{perBCSC|Trainor J}}
</ref>
</ref>


'''Requirements for a Factual Foundation'''<br>
'''Requirements for a Factual Foundation'''<br>
Before a judge can rely upon an expert opinion, the expert must give evidence on the factual foundation relied upon to form the opinion.<ref>
Before a judge can rely upon an expert opinion, the expert must give evidence on the factual foundation relied upon to form the opinion.<ref>
R v Neil, [http://canlii.ca/t/22tpj 1957 CanLII 70] (SCC), [1957] SCR 685{{Plurality}}<br>
''R v Neil'', [http://canlii.ca/t/22tpj 1957 CanLII 70] (SCC), [1957] SCR 685{{Plurality}}<br>
R v Dietrich, [http://canlii.ca/t/g1bt2 1970 CanLII 377] (ON CA){{perONCA|Gale CJ}}<br>
''R v Dietrich'', [http://canlii.ca/t/g1bt2 1970 CanLII 377] (ON CA){{perONCA|Gale CJ}}<br>
</ref>
</ref>
Where the underlying facts are not established in evidence, the judge cannot rely upon the opinion.<ref>
Where the underlying facts are not established in evidence, the judge cannot rely upon the opinion.<ref>
R v Abbey, [http://canlii.ca/t/1lpcd 1982 CanLII 25] (SCC), [1982] 2 SCR 24{{perSCC|Dickson J}} ("Before any weight can be given to an expert's opinion, the facts upon which the opinion is based must be found to exist.")<br>
''R v Abbey'', [http://canlii.ca/t/1lpcd 1982 CanLII 25] (SCC), [1982] 2 SCR 24{{perSCC|Dickson J}} ("Before any weight can be given to an expert's opinion, the facts upon which the opinion is based must be found to exist.")<br>
R v Morgentaler (No. 2) (1973), 14 CCC (2d) 450 (Que. S.C.), [http://canlii.ca/t/htxsb 1973 CanLII 1462] (QC CQ){{perQCCQ|Hugessen ACJ}}
R v Morgentaler (No. 2) (1973), 14 CCC (2d) 450 (Que. S.C.), [http://canlii.ca/t/htxsb 1973 CanLII 1462] (QC CQ){{perQCCQ|Hugessen ACJ}}
R v Lupien, [1970] SCR 263, [http://canlii.ca/t/1xd5k 1969 CanLII 55] (SCC){{Plurality}}<br>
''R v Lupien'', [1970] SCR 263, [http://canlii.ca/t/1xd5k 1969 CanLII 55] (SCC){{Plurality}}<br>
{{supra1|Howard}}<br>
{{supra1|Howard}}<br>
R v Phillion, [http://canlii.ca/t/1tx3f 1977 CanLII 23] (SCC), [1978] 1 SCR 18{{perSCC|Ritchie J}}<br>
''R v Phillion'', [http://canlii.ca/t/1tx3f 1977 CanLII 23] (SCC), [1978] 1 SCR 18{{perSCC|Ritchie J}}<br>
</ref>
</ref>


The evidence relied upon for the opinion can include second-hand evidence, but that the it may affect the weight accorded to the opinion.<ref>
The evidence relied upon for the opinion can include second-hand evidence, but that the it may affect the weight accorded to the opinion.<ref>
R v Alcantara, [http://canlii.ca/t/fqvvj 2012 ABQB 225] (CanLII){{perABQB|Greckol J}}, at para 125<br>
''R v Alcantara'', [http://canlii.ca/t/fqvvj 2012 ABQB 225] (CanLII){{perABQB|Greckol J}}, at para 125<br>
</ref>
</ref>


'''Evaluating Conflicting Expert Evidence'''<br>
'''Evaluating Conflicting Expert Evidence'''<br>
Where the evidence of multiple experts conflict, it is not a matter of chosing one expert over the other, but rather giving weight to each expert and review the opinions as a whole.<ref>
Where the evidence of multiple experts conflict, it is not a matter of chosing one expert over the other, but rather giving weight to each expert and review the opinions as a whole.<ref>
R v Jonkman, [http://canlii.ca/t/fvfwq 2012 SKQB 511] (CanLII){{perSKQB|Schwann J}} at para 97<br>
''R v Jonkman'', [http://canlii.ca/t/fvfwq 2012 SKQB 511] (CanLII){{perSKQB|Schwann J}} at para 97<br>
Toneguzza-Norvell v Burnaby Hospital, [http://canlii.ca/t/1frwb 1994 CanLII 106] (SCC), [1994] 1 SCR 114{{perSCC|McLachlin J}}<br>
Toneguzza-Norvell v Burnaby Hospital, [http://canlii.ca/t/1frwb 1994 CanLII 106] (SCC), [1994] 1 SCR 114{{perSCC|McLachlin J}}<br>
Housen v Nikulaison, [http://canlii.ca/t/51tl 2002 SCC 33] (CanLII), [2002] 2 SCR 235{{perSCC|Iacobucci and Major JJ}}<br>
Housen v Nikulaison, [http://canlii.ca/t/51tl 2002 SCC 33] (CanLII), [2002] 2 SCR 235{{perSCC|Iacobucci and Major JJ}}<br>
Line 222: Line 222:
'''Evaluating Expert Evidence Without A Conflicting Evidence'''<br>
'''Evaluating Expert Evidence Without A Conflicting Evidence'''<br>
A judge need not believe or make any findings of fact based on the testimony of an expert witness due to the failure of the other side to adduce contradicting evidence.<ref>
A judge need not believe or make any findings of fact based on the testimony of an expert witness due to the failure of the other side to adduce contradicting evidence.<ref>
R v Doodnaught, [http://canlii.ca/t/h6m5m 2017 ONCA 781] (CanLII){{perONCA|Watt JA}}, at para 124 ("...as with the testimony of any witness, a trial judge need not believe or make findings of fact based on the testimony of an expert witness simply because no witness is called by the opposite party or evidence adduced to contradict it")<br>
''R v Doodnaught'', [http://canlii.ca/t/h6m5m 2017 ONCA 781] (CanLII){{perONCA|Watt JA}}, at para 124 ("...as with the testimony of any witness, a trial judge need not believe or make findings of fact based on the testimony of an expert witness simply because no witness is called by the opposite party or evidence adduced to contradict it")<br>
''R v Moke'' (1917), [http://canlii.ca/t/gw70b 1917 CanLII 426] (AB CA), 28 CCC 296 (Alta. S.C., A.D.){{perABCA|Walsh J}}, at p. 300<br>
''R v Moke'' (1917), [http://canlii.ca/t/gw70b 1917 CanLII 426] (AB CA), 28 CCC 296 (Alta. S.C., A.D.){{perABCA|Walsh J}}, at p. 300<br>
</ref>
</ref>
Line 229: Line 229:


===Hypothetical Questions===
===Hypothetical Questions===
The opinion evidence can be related by way of hypothetical questions put to the expert.<ref> R v Fiqia, [http://canlii.ca/t/2dbft 1994 ABCA 402] (CanLII), (1994) 162 A.R. 117 (C.A.){{perABCA|Hunt JA}}</ref> However, the testimony cannot be "oath-helping" evidence.<ref> R v Reid, [http://canlii.ca/t/6g6g 2003 CanLII 14779] (ON C.A.){{perONCA|Moldaver JA}}</ref>  
The opinion evidence can be related by way of hypothetical questions put to the expert.<ref> ''R v Fiqia'', [http://canlii.ca/t/2dbft 1994 ABCA 402] (CanLII), (1994) 162 A.R. 117 (C.A.){{perABCA|Hunt JA}}</ref> However, the testimony cannot be "oath-helping" evidence.<ref> ''R v Reid'', [http://canlii.ca/t/6g6g 2003 CanLII 14779] (ON C.A.){{perONCA|Moldaver JA}}</ref>  


The hypotheticals can be put to the expert where the facts are not in dispute.<ref>R v Bleta, [http://canlii.ca/t/1tvsq 1964 CanLII 14] (SCC), [1964] SCR 561{{perSCC|Ritchie J}}</ref>  If the underlying facts are in dispute the opinion cannot remove the fact-finding function of the trier-of-fact.<ref>''R v PG'', [http://canlii.ca/t/224d8 2009 ONCA 32] (CanLII){{perONCA|Juriansz JA}}</ref> The cross-examiner can put to the expert any proven or provable facts to determine whether it alters the confidence of the opinion.<ref>R v Kerr, [http://canlii.ca/t/533d 2000 BCCA 209] (CanLII){{perBCCA|McEachern CJ}}</ref>
The hypotheticals can be put to the expert where the facts are not in dispute.<ref>''R v Bleta'', [http://canlii.ca/t/1tvsq 1964 CanLII 14] (SCC), [1964] SCR 561{{perSCC|Ritchie J}}</ref>  If the underlying facts are in dispute the opinion cannot remove the fact-finding function of the trier-of-fact.<ref>''R v PG'', [http://canlii.ca/t/224d8 2009 ONCA 32] (CanLII){{perONCA|Juriansz JA}}</ref> The cross-examiner can put to the expert any proven or provable facts to determine whether it alters the confidence of the opinion.<ref>''R v Kerr'', [http://canlii.ca/t/533d 2000 BCCA 209] (CanLII){{perBCCA|McEachern CJ}}</ref>


It can be preferrable to ask questions in hypothetical form on contradictory matters in order to avoid overly influencing the jury's fact-finding process.<ref>
It can be preferrable to ask questions in hypothetical form on contradictory matters in order to avoid overly influencing the jury's fact-finding process.<ref>
R v Leinen, [http://canlii.ca/t/g01l8 2013 ABCA 283] (CanLII){{perABCA|Hunt JA}} (2:1)
''R v Leinen'', [http://canlii.ca/t/g01l8 2013 ABCA 283] (CanLII){{perABCA|Hunt JA}} (2:1)
</ref>
</ref>


The party seeking to rely on an expert opinion based on a hypothetical fact has the burden of establishing those underlying facts.<ref>
The party seeking to rely on an expert opinion based on a hypothetical fact has the burden of establishing those underlying facts.<ref>
R v Lavallee, [1990] 1 SCR 852, [http://canlii.ca/t/1fsx3 1990 CanLII 95] (SCC){{perSCC|Wilson J}}<br>
''R v Lavallee'', [1990] 1 SCR 852, [http://canlii.ca/t/1fsx3 1990 CanLII 95] (SCC){{perSCC|Wilson J}}<br>
R v Flight, [http://canlii.ca/t/g711g 2014 ABCA 185] (CanLII){{perABCA|Veldhuis JA}}<br>
''R v Flight'', [http://canlii.ca/t/g711g 2014 ABCA 185] (CanLII){{perABCA|Veldhuis JA}}<br>
</ref>
</ref>


Line 248: Line 248:
R v Béland, [http://canlii.ca/t/1ftm1 1987 CanLII 27] (SCC), [1987] 2 SCR 398{{perSCC|McIntyre J}}
R v Béland, [http://canlii.ca/t/1ftm1 1987 CanLII 27] (SCC), [1987] 2 SCR 398{{perSCC|McIntyre J}}
</ref> This is not a strict rule as it should be determined on a case-by-case.<ref>
</ref> This is not a strict rule as it should be determined on a case-by-case.<ref>
R v Potts, [http://canlii.ca/t/hr64n 2018 ONCA 294] (CanLII){{TheCourtONCA}}, at para 47 ("It is worth recalling that no general rule precludes the introduction of expert opinion evidence on the ultimate issue in a criminal trial")<br>
''R v Potts'', [http://canlii.ca/t/hr64n 2018 ONCA 294] (CanLII){{TheCourtONCA}}, at para 47 ("It is worth recalling that no general rule precludes the introduction of expert opinion evidence on the ultimate issue in a criminal trial")<br>
R v Mohan, [http://canlii.ca/t/1frt1 1994 CanLII 80] (SCC), [1994] 2 SCR 9{{perSCC|Sopinka J}}, at pp. 24-25<br>
''R v Mohan'', [http://canlii.ca/t/1frt1 1994 CanLII 80] (SCC), [1994] 2 SCR 9{{perSCC|Sopinka J}}, at pp. 24-25<br>
''R v Bryan'' (2003), [http://canlii.ca/t/6xxg 2003 CanLII 24337] (ON CA), 175 CCC (3d) 285 (Ont. C.A.){{perONCA|Goudge JA}}, at paras. 16-17<br>
''R v Bryan'' (2003), [http://canlii.ca/t/6xxg 2003 CanLII 24337] (ON CA), 175 CCC (3d) 285 (Ont. C.A.){{perONCA|Goudge JA}}, at paras. 16-17<br>
R v Lucas, [http://canlii.ca/t/g84mv 2014 ONCA 561] (CanLII), 121 O.R. (3d) 303{{TheCourtONCA}}, at para. 271<br>
''R v Lucas'', [http://canlii.ca/t/g84mv 2014 ONCA 561] (CanLII), 121 O.R. (3d) 303{{TheCourtONCA}}, at para. 271<br>
</ref>
</ref>
Where the facts are not in dispute there is a discretion for the judge to allow the expert to give evidence on the ultimate issue.<ref>
Where the facts are not in dispute there is a discretion for the judge to allow the expert to give evidence on the ultimate issue.<ref>
Line 258: Line 258:


A psychologist has been allowed to give evidence on whether a murder was "planned and deliberate".<ref>
A psychologist has been allowed to give evidence on whether a murder was "planned and deliberate".<ref>
R v More, [http://canlii.ca/t/22vz3 1963 CanLII 79] (SCC), [1963] SCR 522{{perSCC|Cartwright J}}
''R v More'', [http://canlii.ca/t/22vz3 1963 CanLII 79] (SCC), [1963] SCR 522{{perSCC|Cartwright J}}
</ref> Also whether the accused's condition is a "disease of the mind".<ref>
</ref> Also whether the accused's condition is a "disease of the mind".<ref>
R v Cooper, [http://canlii.ca/t/1tx9m 1979 CanLII 63] (SCC), [1980] 1 SCR 1149{{perSCC|Dickson J}}
''R v Cooper'', [http://canlii.ca/t/1tx9m 1979 CanLII 63] (SCC), [1980] 1 SCR 1149{{perSCC|Dickson J}}
</ref>
</ref>
{{reflist|2}}
{{reflist|2}}
Line 266: Line 266:
===Specific Types of Expert===
===Specific Types of Expert===
'''Drug Expert'''<br>
'''Drug Expert'''<br>
A lay person such as an RCMP officer cannot be a reliable expert simply by "conducting numerous casual conversations with drug users or traffickers."  This sort of "[a]necdotal evidence cannot be tested or verified hearsay must be supplemented and supported by some form of admissible evidence."<ref>R v Klassen, [http://canlii.ca/t/26j 2003 MBQB 253] (CanLII), [2003] M.J. No. 417{{perMBQB|Scurfield J}}</ref>
A lay person such as an RCMP officer cannot be a reliable expert simply by "conducting numerous casual conversations with drug users or traffickers."  This sort of "[a]necdotal evidence cannot be tested or verified hearsay must be supplemented and supported by some form of admissible evidence."<ref>''R v Klassen'', [http://canlii.ca/t/26j 2003 MBQB 253] (CanLII), [2003] M.J. No. 417{{perMBQB|Scurfield J}}</ref>


{{Reflist|2}}
{{Reflist|2}}
Line 275: Line 275:
===Opinion Evidence Outside of Qualification===
===Opinion Evidence Outside of Qualification===
Where a qualified expert testifies to matters directly outside of their area of qualification but is clearly within their area of special knowledge, the evidence can still be accepted absent any objection to the evidence by the opposing side.<ref>
Where a qualified expert testifies to matters directly outside of their area of qualification but is clearly within their area of special knowledge, the evidence can still be accepted absent any objection to the evidence by the opposing side.<ref>
R v Marquard, [http://canlii.ca/t/1frx2 1993 CanLII 37] (SCC), [1993] 4 SCR 223{{perSCC|McLachlin J}} at pp. 242-44</ref>
''R v Marquard'', [http://canlii.ca/t/1frx2 1993 CanLII 37] (SCC), [1993] 4 SCR 223{{perSCC|McLachlin J}} at pp. 242-44</ref>
Likewise, a technical failure to qualify someone who clearly has expertise in the area, absent any objections, should be permitted to give expert evidence.<ref>
Likewise, a technical failure to qualify someone who clearly has expertise in the area, absent any objections, should be permitted to give expert evidence.<ref>
Marquard at pp. 242-44</ref>
Marquard at pp. 242-44</ref>
Line 284: Line 284:


There is some difference in opinion of whether or not expert qualification is needed to present evidence from cell phone towers.<ref>
There is some difference in opinion of whether or not expert qualification is needed to present evidence from cell phone towers.<ref>
R v Hamilton, [http://canlii.ca/t/fljvz 2011 ONCA 399] (CanLII){{TheCourtONCA}} at paras 273 to 284 - evidence from phone company as to the mechanical workings of cell towers and their relationship to the cell phone<br>
''R v Hamilton'', [http://canlii.ca/t/fljvz 2011 ONCA 399] (CanLII){{TheCourtONCA}} at paras 273 to 284 - evidence from phone company as to the mechanical workings of cell towers and their relationship to the cell phone<br>
R v Ranger, [http://canlii.ca/t/2db2k 2010 ONCA 759] (CanLII){{TheCourtONCA}} -- cell phone tower evidence accepted without qualification for ''general'' location evidence<br>
''R v Ranger'', [http://canlii.ca/t/2db2k 2010 ONCA 759] (CanLII){{TheCourtONCA}} -- cell phone tower evidence accepted without qualification for ''general'' location evidence<br>
c.f. R v Korski, [http://canlii.ca/t/236fj 2009 MBCA 37] (CanLII){{perMBCA|Steel JA}} -- required expert to testify on cell tower evidence<br>
c.f. ''R v Korski'', [http://canlii.ca/t/236fj 2009 MBCA 37] (CanLII){{perMBCA|Steel JA}} -- required expert to testify on cell tower evidence<br>
</ref>  
</ref>  
It is generally accepted that even where it is not necessary, it is useful to explain some of the records.<ref>
It is generally accepted that even where it is not necessary, it is useful to explain some of the records.<ref>
Line 293: Line 293:


Evidence on the regular functioning of social media websites can in circumstances be accepted without qualification.<ref>
Evidence on the regular functioning of social media websites can in circumstances be accepted without qualification.<ref>
R v Soh, [http://canlii.ca/t/g50jc 2014 NBQB 20] (CanLII){{perNBQB|LaVigne J}}
''R v Soh'', [http://canlii.ca/t/g50jc 2014 NBQB 20] (CanLII){{perNBQB|LaVigne J}}
</ref>
</ref>



Revision as of 10:14, 13 January 2019

General Principles

Expert opinion is testimonial evidence that gives an opinion on facts perceived by him or another that concerns an issue that is likely outside the experience and knowledge of the trier-of-fact (i.e. a lay person). [1] The expert must have special knowledge in the matter [2] and the opinion must be reasonably necessary to assist the trier-of-fact to make a proper judgment. [3] There must also be no exclusionary rules that would otherwise prohibit the evidence from being given. [4]

A person testifying to specialized knowledge will not necessarily be required to be qualified as an expert. Where they testify to their "factual knowledge" based on their "knowledge, observations and experience".[5]

An expert who testifies to direct observation without opinion is not subject to the opinion rule of exclusion. This evidence is admitted in the same way as eye-witness evidence.[6]

The expert is not to testify to facts, but rather only opinion to allow the trier-of-fact to draw inferences. [7]

Relevance
Relevance is "a threshold requirement" to admitting expert evidence.[8]

Specialization
The key requirement for expert evidence is that the expert "possesses special knowledge and experience going beyond that of the trier of fact".[9] As long as the court is satisfied that the witness is sufficiently experienced he should be qualified.[10]

Any deficiencies of the knowledge or opinion simply goes to weight.[11]

The means by which the skill, expertise, or knowledge was acquired goes to weight and not admissibility.[12] It is acceptable to obtain the ability to give an opinion from study, instruction, practical experience or observations. Formal study in not necessary.[13]

Practice
An expert in any type of litigation has duties and responsibilities that include:[14]

  1. Expert evidence presented to the court should be, and should be seen to be, the independent product of the expert uninfluenced as to form or content by the exigencies of litigation.
  2. An expert witness should provide independent assistance to the court by way of objective unbiased opinion in relation to matters within his [or her] expertise. An expert witness . . . should never assume the role of an advocate.
  3. An expert witness should state the facts or assumptions upon which his [or her] opinion is based. He [or she] should not omit to consider material facts which could detract from his [or her] concluded opinion.
  4. An expert witness should make it clear when a particular question or issue falls outside his [or her] expertise.
  5. If an expert's opinion is not properly researched because he [or she] considers [there to be] insufficient data . . . available, then this must be stated with an indication that the opinion is no more than a provisional one. In cases where an expert witness, who has prepared a report could not assert that the report contained the truth, the whole truth and nothing but the truth without some qualification, that qualification should be stated in the report

The expert's right to give opinion evidence imports an obligation of maintaining an attitude of "strict independence and impartiality".[15]

It has been recommended that an "evidence-based approach" be taken to evaluate experts. This suggests four requirements:[16]

  1. the theory or technique utilized by the expert must be reliable, and used in a manner that is reliable;
  2. the expert must keep an open mind to a "broad menu of possibilities" (not be biased);
  3. the expert must be objective and comprehensive in collecting evidence -- including rejecting information not germane and transparent about the information and influences involved; and
  4. the expert must proffer more than the mere opinion, including the complete reasoning process, shortcomings and fair guidance on the confidence in the opinion.

Jury Instruction
Wher qualified expert gives opinion evidence outside of their field, the problem can generally be remedied through a "remedial instruction advising the jury to disabuse their minds of the inadmissible evidence".[17]

Standard of Review
Trial judges are entitled to "wide discretion" and deference when weighing the costs and benefits of admitting expert evidence.[18]

Whether someone can be qualified as an expert is a question of law and is reviewable on a standard of correctness.[19]

  1. Folkes v Chadd (1782), 3 Dougl. 157
    R v J-L J, [2000] 2 SCR 600, 2000 SCC 51 (CanLII), per Binnie J at para 56
    R v Abbey, 1982 CanLII 25 (SCC), [1982] 2 SCR 24, per Dickson J
    R v Mohan 1994 CanLII 80 (SCC), [1994] 2 SCR 9, per Sopinka J at 413 (the opinion must "provide information ‘which is likely to be outside the experience or knowledge of’” the trier of fact")
    R v Bunniss (1964), 44 CR 262 (BC Co. Ct.), 1964 CanLII 673 (BC SC), per Tyrwhitt-Drake J (an expert is "one who has by dint of training and practice, acquired a good knowledge of the science or art concerning which his opinion is sought, and the practical ability to use his judgment in that science")
  2. R v Terceira, 1998 CanLII 2174 (ON CA), (1998) 123 CCC 1 (Ont. CA), per Finlayson JA Mohan, supra at p. 414 (the witness must be “shown to have acquired special or peculiar knowledge through study or experience in respect of the matters on which he or she undertakes to testify”)
  3. Mohan, supra
    R v Lovie, 1995 CanLII 801 (ON CA), per Finlayson JA
  4. R v NO, 2009 ABCA 75 (CanLII), per curiam at para 19
  5. R v Hamilton, 2011 ONCA 399 (CanLII), per curiam at paras 273 to 284 - evidence from phone company as to the mechanical workings of cell towers and their relationship to the cell phone
    R v Ranger, 2010 ONCA 759 (CanLII), per curiam -- cell phone tower evidence
    c.f. R v Korski, 2009 MBCA 37 (CanLII), per Steel JA -- required expert to testify on cell tower evidence
  6. R v KA, 1999 CanLII 3793 (ON CA), per Charron JA at para 72
  7. R v Parrott, 2001 SCC 3 (CanLII), [2001] 1 SCR 178, per Binnie J
    R v Lavallee, 1990 CanLII 95 (SCC), [1990] 1 SCR 852, per Wilson J
  8. Mohan, supra at p. 411
  9. R v Béland, 1987 CanLII 27 (SCC), [1987] 2 SCR 398, per McIntyre J at p. 415
    R v Marquard, 1993 CanLII 37 (SCC), [1993] 4 SCR 223, per McLachlin J at para 35
    R v Chan, 1993 ABCA 383 (CanLII), (1993), 145 A.R. 304, per curiam at para 9
  10. Chan, ibid. at para 9
  11. Chan, ibid. at para 9
  12. Chan at para 9 citing Sopinka, Lederman and Bryant, The Law of Evidence of Canada (1992), at pp. 536‑537: ("As long as the court is satisfied that the witness is sufficiently experienced in the subject matter at issue, the court will not be concerned with whether his or her skill was derived from specific studies or by practical training, although that may affect the weight to be given to the evidence.") R v Rayner, 2000 NSCA 143 (CanLII), 189 N.S.R. (2d) 144, per Saunders JA
  13. R v Melaragni, (1992), 73 CCC (3d) 348 (Ont. Ct. Gen. Div.), 1992 CanLII 12764 (ON SC), per Moldaver JA
    R v NO, 2009 ABCA 75 (CanLII), per curiam at para 22
  14. Bedford v Canada, 2010 ONSC 4264 (CanLII), per Himel J, at para 100 - upheld on appeal 2013 SCC 72
    see also National Justice Compania Naviera SA v Prudential Assurance Co. (The "Ikarian Reefer"), [1993] 2 Lloyd's Rep. 68 (Q.B. (Comm. Ct.)), at pp. 81-82
  15. Bedford, supra at para 101
  16. see Bedford at para 102 - referencing the Goudge Inquiry
    Professor David Paciocco in "Taking a 'Goudge' out of Bluster and Blarney: an 'Evidence-Based Approach' to Expert Testimony" (2009), 13 Can. Crim. L.R. 135
  17. R v Sekhon, 2014 SCC 15 (CanLII)(link pending), per Moldaver J at para 48
  18. R v Clark, 2016 ABCA 72 (CanLII), per curiam, at para 59 to 62
    R v DD, 2000 SCC 43 (CanLII), per Major J at para 13
    R v Soni, 2016 ABCA 231 (CanLII), per curiam (2:1) at para 8
    R v Dominic, 2016 ABCA 114 (CanLII), per curiam at para 17
    R v Abbey, 2009 ONCA 624 (CanLII), per Doherty JA at para 97, leave to appeal to SCC refused
  19. R v Bear (C.W.), 2013 MBCA 96 (CanLII), per Steel JA at para 81

Requirements of Expert Evidence ("Mohan" Test)

Procedure

Evidence

Once the witness is qualified as an expert they are permitted to give evidence in the area for which they were qualified.

The expert must cite the bases on his opinion in order for the trier-of-fact to evaluate the opinion. [1] The expert can use sources and information found in the "scope of his or her expertise"[2] as well as sources outside his knowledge in limited contexts.[3] The "second hand" evidence of texts is not admissible as evidence, but can be used to show the information on which the opinion is based.[4]

An expert may be cross-examined on a text, report or article relating to his area of expertise. [5] The expert can only comment on works they are familiar with. If the expert acknowledges the authority, the examiner may read parts of the document to the witness to the extent that it is accepted as valid. Those confirmed passages will become evidence in the case[6]

A judge may reject the uncontradicted expert evidence as unreasonable. [7] The evidence should not be rejected if there is no contradictory evidence and the opinion is not seriously challenged.[8]

The expert cannot recite statistical evidence of probabilities based on prior similar events to infer what likely occurred in the incident at issue.[9]

The expert may not give anecdotal evidence concerning prior similar events to suggest an opinion about the event at issue.[10]

Area of Expertise
The qualified "area of expertise" does not need to articulate the exact subject matter to which they will give evidence. It often sufficient to articulate the general area of knowledge.[11]

Use of Report
It is common-place that an expert may testify with their reports on hand and may refer to them during testimony.[12]

There is some division of wehther an expert report should be filed as an exhibit.[13]

  1. R v Neil, 1957 CanLII 70 (SCC), [1957] SCR 685
    R v Grandinetti, 2003 ABCA 307 (CanLII), per McFadyen JA (2:1)
    R v Trudel, 1994 CanLII 5397 (QC CA), per Brossard JA
  2. R v SAB, 2003 SCC 60 (CanLII), [2003] 2 SCR 678, per Arbour J at para 63
  3. R v Anderson (1914), 22 CCC 455, 1914 CanLII 361 (AB CA), per Harvey J
    R v Godfrey, 1974 ALTASCAD 43 (CanLII), [1974] 4 W.W.R. 677, 18 CCC (2d) 90 (Alta. C.A.) (2:1), at pp. 102-104
  4. R v Burns, 1994 CanLII 127 (SCC), [1994] 1 SCR 656, per McLachlin J
  5. R c Taillefer, 1995 CanLII 4592 (QCCA), per Proulx JA
    R v Marquard, 1993 CanLII 37 (SCC), [1993] 4 SCR 223, per McLachlin J
  6. Marquard, ibid. ("...in examining an expert witness on other expert opinions found in papers or books is to ask the witness if he or she knows the work. If the answer is "no", or if the witness denies the work's authority, that is the end of the matter. ...If the answer is "yes", and the witness acknowledges the work's authority, then the witness has confirmed it by the witness's own testimony. Parts of it may be read to the witness, and to the extent they are confirmed, they become evidence in the case.")
  7. R v Prince, (1971), 6 CCC (2d) 183 (Ont. C.A.), 1971 CanLII 1285 (ON CA), per Gale CJ
    R v Lambkin, 2002 MBCA 157 (CanLII), per Monnin JA
  8. R v Molodowic, 2000 SCC 16 (CanLII), [2000] 1 SCR 420, per Arbour J
  9. R v Klymchuk (2005), 2005 CanLII 44167 (ON CA), 203 CCC (3d) 341 (Ont. C.A.), per Doherty JA, at para. 46. R v Shafia, 2016 ONCA 812 (CanLII), per Watt JA, at para 242 ("An expert is not entitled to give statistical evidence of probabilities based on prior similar events to support a conclusion about what happened on the occasion that forms the subject-matter of charges")
  10. Shafia, ibid. at para 243 ("Experts may not give anecdotal evidence gathered from prior experiences in proffering their opinion about conduct on a particular occasion. The evidence lacks legal relevance and is apt to engender significant prejudice, especially when adduced to rebut a defence")
    Sekhon, supra, at paras 49 to 50
  11. e.g. R v Rothgordt, 2017 BCCA 230 (CanLII), per Frankel JA, at para 16
  12. R v Sandham, [2009] OJ No 4517 (Ont. S.C.J.), 2009 CanLII 58982 (ON SC), per Heeney J ("Experts are routinely permitted to have their reports in front of them as they testify, and to refer to them as they deliver their evidence. Such reports are frequently entered as exhibits.")
  13. R v Millard and Smich, 2016 ONSC 1517 (CanLII), per Goodman J (" Generally speaking, I agree that experts’ reports, per se, ought not to be filed as exhibits. The evidence is their “in-court” testimony. ")

Weight of Opinion

Expert opinion on anything that is not necessary for the trier-of-fact to make findings is not admissible.[1]

The opinion evidence given must be within the qualified field of expertise.[2]

The expert need not have personal knowledge of any facts to give an opinion.[3]

A jury must be instructed that the hearsay evidence of the facts underlying the experts opinion is not admissible for any purpose other than to evaluate the weight of the opinion.[4]

The weight given to an opinion is a question of fact.[5]

The opinion must be specific to the case and not simply in generalities.[6]

Requirements for a Factual Foundation
Before a judge can rely upon an expert opinion, the expert must give evidence on the factual foundation relied upon to form the opinion.[7] Where the underlying facts are not established in evidence, the judge cannot rely upon the opinion.[8]

The evidence relied upon for the opinion can include second-hand evidence, but that the it may affect the weight accorded to the opinion.[9]

Evaluating Conflicting Expert Evidence
Where the evidence of multiple experts conflict, it is not a matter of chosing one expert over the other, but rather giving weight to each expert and review the opinions as a whole.[10]

Evaluating Expert Evidence Without A Conflicting Evidence
A judge need not believe or make any findings of fact based on the testimony of an expert witness due to the failure of the other side to adduce contradicting evidence.[11]

  1. R v Howard, 1989 CanLII 99 (SCC), [1989] 1 SCR 1337, per Lamer J
    R v Béland, 1987 CanLII 27 (SCC), [1987] 2 SCR 398, per McIntyre J R v Millar, (1989), 49 CCC (3d) 193 (ONCA), 1989 CanLII 7151 (ON CA), per Morden JA, at 220
  2. Howard, supra
    Millar, supra
  3. Preeper and Doyle, 1888 CanLII 56 (SCC), (1888), 15 SCR 401
  4. R v Babcock, 1984 ABCA 291 (CanLII), per Moir JA
  5. R v Smithers, 1977 CanLII 7 (SCC), [1978] 1 SCR 506, per Dickson J
  6. R v Li, 1980 CanLII 344 (BC SC), per Trainor J
  7. R v Neil, 1957 CanLII 70 (SCC), [1957] SCR 685
    R v Dietrich, 1970 CanLII 377 (ON CA), per Gale CJ
  8. R v Abbey, 1982 CanLII 25 (SCC), [1982] 2 SCR 24, per Dickson J ("Before any weight can be given to an expert's opinion, the facts upon which the opinion is based must be found to exist.")
    R v Morgentaler (No. 2) (1973), 14 CCC (2d) 450 (Que. S.C.), 1973 CanLII 1462 (QC CQ), per Hugessen ACJ R v Lupien, [1970] SCR 263, 1969 CanLII 55 (SCC)
    Howard, supra
    R v Phillion, 1977 CanLII 23 (SCC), [1978] 1 SCR 18, per Ritchie J
  9. R v Alcantara, 2012 ABQB 225 (CanLII), per Greckol J, at para 125
  10. R v Jonkman, 2012 SKQB 511 (CanLII), per Schwann J at para 97
    Toneguzza-Norvell v Burnaby Hospital, 1994 CanLII 106 (SCC), [1994] 1 SCR 114, per McLachlin J
    Housen v Nikulaison, 2002 SCC 33 (CanLII), [2002] 2 SCR 235, per Iacobucci and Major JJ
  11. R v Doodnaught, 2017 ONCA 781 (CanLII), per Watt JA, at para 124 ("...as with the testimony of any witness, a trial judge need not believe or make findings of fact based on the testimony of an expert witness simply because no witness is called by the opposite party or evidence adduced to contradict it")
    R v Moke (1917), 1917 CanLII 426 (AB CA), 28 CCC 296 (Alta. S.C., A.D.), per Walsh J, at p. 300

Hypothetical Questions

The opinion evidence can be related by way of hypothetical questions put to the expert.[1] However, the testimony cannot be "oath-helping" evidence.[2]

The hypotheticals can be put to the expert where the facts are not in dispute.[3] If the underlying facts are in dispute the opinion cannot remove the fact-finding function of the trier-of-fact.[4] The cross-examiner can put to the expert any proven or provable facts to determine whether it alters the confidence of the opinion.[5]

It can be preferrable to ask questions in hypothetical form on contradictory matters in order to avoid overly influencing the jury's fact-finding process.[6]

The party seeking to rely on an expert opinion based on a hypothetical fact has the burden of establishing those underlying facts.[7]

  1. R v Fiqia, 1994 ABCA 402 (CanLII), (1994) 162 A.R. 117 (C.A.), per Hunt JA
  2. R v Reid, 2003 CanLII 14779 (ON C.A.), per Moldaver JA
  3. R v Bleta, 1964 CanLII 14 (SCC), [1964] SCR 561, per Ritchie J
  4. R v PG, 2009 ONCA 32 (CanLII), per Juriansz JA
  5. R v Kerr, 2000 BCCA 209 (CanLII), per McEachern CJ
  6. R v Leinen, 2013 ABCA 283 (CanLII), per Hunt JA (2:1)
  7. R v Lavallee, [1990] 1 SCR 852, 1990 CanLII 95 (SCC), per Wilson J
    R v Flight, 2014 ABCA 185 (CanLII), per Veldhuis JA

Ultimate Issue Rule

An expert should generally not give an opinion on an "ultimate issue" to the case otherwise the expert would usurp the role of the trier-of-fact.[1] This is not a strict rule as it should be determined on a case-by-case.[2] Where the facts are not in dispute there is a discretion for the judge to allow the expert to give evidence on the ultimate issue.[3]

A psychologist has been allowed to give evidence on whether a murder was "planned and deliberate".[4] Also whether the accused's condition is a "disease of the mind".[5]

  1. R v Béland, 1987 CanLII 27 (SCC), [1987] 2 SCR 398, per McIntyre J
  2. R v Potts, 2018 ONCA 294 (CanLII), per curiam, at para 47 ("It is worth recalling that no general rule precludes the introduction of expert opinion evidence on the ultimate issue in a criminal trial")
    R v Mohan, 1994 CanLII 80 (SCC), [1994] 2 SCR 9, per Sopinka J, at pp. 24-25
    R v Bryan (2003), 2003 CanLII 24337 (ON CA), 175 CCC (3d) 285 (Ont. C.A.), per Goudge JA, at paras. 16-17
    R v Lucas, 2014 ONCA 561 (CanLII), 121 O.R. (3d) 303, per curiam, at para. 271
  3. Swietlinski v R, 1978 CanLII 56 (ON CA), per Martin JA
  4. R v More, 1963 CanLII 79 (SCC), [1963] SCR 522, per Cartwright J
  5. R v Cooper, 1979 CanLII 63 (SCC), [1980] 1 SCR 1149, per Dickson J

Specific Types of Expert

Drug Expert
A lay person such as an RCMP officer cannot be a reliable expert simply by "conducting numerous casual conversations with drug users or traffickers." This sort of "[a]necdotal evidence cannot be tested or verified hearsay must be supplemented and supported by some form of admissible evidence."[1]

  1. R v Klassen, 2003 MBQB 253 (CanLII), [2003] M.J. No. 417, per Scurfield J

Example Fields of Qualifications

Opinion Evidence Outside of Qualification

Where a qualified expert testifies to matters directly outside of their area of qualification but is clearly within their area of special knowledge, the evidence can still be accepted absent any objection to the evidence by the opposing side.[1] Likewise, a technical failure to qualify someone who clearly has expertise in the area, absent any objections, should be permitted to give expert evidence.[2]

  1. R v Marquard, 1993 CanLII 37 (SCC), [1993] 4 SCR 223, per McLachlin J at pp. 242-44
  2. Marquard at pp. 242-44

Where Technical Evidence Does Not Require Expert Evidence

There is some difference in opinion of whether or not expert qualification is needed to present evidence from cell phone towers.[1] It is generally accepted that even where it is not necessary, it is useful to explain some of the records.[2]

Evidence on the regular functioning of social media websites can in circumstances be accepted without qualification.[3]

  1. R v Hamilton, 2011 ONCA 399 (CanLII), per curiam at paras 273 to 284 - evidence from phone company as to the mechanical workings of cell towers and their relationship to the cell phone
    R v Ranger, 2010 ONCA 759 (CanLII), per curiam -- cell phone tower evidence accepted without qualification for general location evidence
    c.f. R v Korski, 2009 MBCA 37 (CanLII), per Steel JA -- required expert to testify on cell tower evidence
  2. e.g. R v McBean, 2011 ONSC 3125 (CanLII), per Fuerst J
  3. R v Soh, 2014 NBQB 20 (CanLII), per LaVigne J

Case Digests

See Also