How Is Reasonable Doubt Established?
Reasonable Doubt May Be Raised By Presenting Theories That Contain Logically Assessed Inferences With Reasonable Possibility That the Accused Is Without Guilt of the Allegations.
Understanding the Defence Strategy of Raising Reasonable Doubts That May Lead to Dismissed Charges
When an accused is charged, the prosecution must prove the allegations beyond a reasonable doubt. Where a reasonable doubt exists based on a logical possibility that the accused may be without guilt, the accused must be acquitted of the allegation and the charge must be dismissed. Accordingly, when defending an accused person, the defence strategy may involve acceptance of some or all of the evidence presented by the prosecution while presenting and arguing that an alternate theory, being an alternate theory that absolves the accused of the allegations, exists.
Although alternate theories might exist and which may suggest that an accused person is without guilt for the offence alleged, any alternative theories put forth must be logically and rationally presented as reasonably possible whereas, to raise a reasonable doubt, as opposed to just a possible doubt, the doubt raised contain an air of reality, meaning some reasonableness, instead of just a far fetched scenario or unlikely possibility. The requirement of a doubt that is reasonable, meaning a doubt that contains logically and rationally based inferences was explained by the Supreme Court of Canada within R. v. Lifchus, 1997 CanLII 319 (SCC),  3 S.C.R. 320 as well as R. v. Villaroman, 2016 SCC 33 (CanLII),  1 S.C.R. 1000, wherein each case it was respectively stated:
30 It follows that it is certainly not essential to instruct jurors that a reasonable doubt is a doubt for which a reason can be supplied. To do so may unnecessarily complicate the task of the jury. It will suffice to instruct the jury that a reasonable doubt is a doubt based on reason and common sense which must be logically based upon the evidence or lack of evidence.
 At one time, it was said that in circumstantial cases, “conclusions alternative to the guilt of the accused must be rational conclusions based on inferences drawn from proven facts”: see R. v. McIver, 1965 CanLII 26 (ON CA),  2 O.R. 475 (C.A.), at p. 479, aff’d without discussion of this point 1966 CanLII 6 (SCC),  S.C.R. 254. However, that view is no longer accepted. In assessing circumstantial evidence, inferences consistent with innocence do not have to arise from proven facts: R. v. Khela, 2009 SCC 4,  1 S.C.R. 104, at para. 58; see also R. v. Defaveri, 2014 BCCA 370, 361 B.C.A.C. 301, at para. 10; R. v. Bui, 2014 ONCA 614, 14 C.R. (7th) 149, at para. 28. Requiring proven facts to support explanations other than guilt wrongly puts an obligation on an accused to prove facts and is contrary to the rule that whether there is a reasonable doubt is assessed by considering all of the evidence. The issue with respect to circumstantial evidence is the range of reasonable inferences that can be drawn from it. If there are reasonable inferences other than guilt, the Crown’s evidence does not meet the standard of proof beyond a reasonable doubt.
 I agree with the respondent’s position that a reasonable doubt, or theory alternative to guilt, is not rendered “speculative” by the mere fact that it arises from a lack of evidence. As stated by this Court in Lifchus, a reasonable doubt “is a doubt based on reason and common sense which must be logically based upon the evidence or lack of evidence”: para. 30 (emphasis added). A certain gap in the evidence may result in inferences other than guilt. But those inferences must be reasonable given the evidence and the absence of evidence, assessed logically, and in light of human experience and common sense.
 When assessing circumstantial evidence, the trier of fact should consider “other plausible theor[ies]” and “other reasonable possibilities” which are inconsistent with guilt: R. v. Comba, 1938 CanLII 14 (ON CA),  O.R. 200 (C.A.), at pp. 205 and 211, per Middleton J.A., aff’d 1938 CanLII 7 (SCC),  S.C.R. 396; R. v. Baigent, 2013 BCCA 28, 335 B.C.A.C. 11, at para. 20; R. v. Mitchell,  QCA 394 (AustLII), at para. 35. I agree with the appellant that the Crown thus may need to negative these reasonable possibilities, but certainly does not need to “negative every possible conjecture, no matter how irrational or fanciful, which might be consistent with the innocence of the accused”: R. v. Bagshaw, 1971 CanLII 13 (SCC),  S.C.R. 2, at p. 8. “Other plausible theories” or “other reasonable possibilities” must be based on logic and experience applied to the evidence or the absence of evidence, not on speculation.
 Of course, the line between a “plausible theory” and “speculation” is not always easy to draw. But the basic question is whether the circumstantial evidence, viewed logically and in light of human experience, is reasonably capable of supporting an inference other than that the accused is guilty.
As such, being that a reasonable doubt is raised only via logically and rationally based inferences, an accused person must come up with more than far fetched conjecture or outrageous speculation as a means to discredit the case of the prosecution. Raising a reasonable doubt may only arise by presenting evidence or arguing alternative theories about what happened when such are reasonable possibilities. Simply said, for a reasonable doubt to show that the accused may be without guilt and therefore be innocent of the allegations, the reasonable doubt must be reasonably based.
A reasonable doubt may be established based upon a logical and a rational inference that shows a reasonable possibility that the accused person may be innocent of the allegations; however, such a doubt must be reasonable in that the possibility presented must be sensible and supported with some evidence.