How Is Reasonable Doubt Established?
A Reasonable Doubt May Arise By Presenting An Alternate Theory That Is Plausible Meaning Rationally Possible and Thereby Reasonably Capable of Supporting the Inference That the Accused May Be Without Guilt.
A Helpful Guide For How to Determine and Understand When Speculative Alternative Theories May Present a Reasonable Doubt
When a person is accused and charged with a crime or an offence, the case against the accused person must be proven beyond a reasonable doubt. If a reasonable doubt exists, meaning a doubt that is based upon the logical possibility that the accused person may be innocent, then the accused must be acquitted the charge. Accordingly, when defending against a charge the accused person may choose a defence strategy that involves some or even all of the evidence brought forward by the prosecution; however, the defence strategy presents and argues a different theory than presented by the prosecution; a theory that suggests or demonstrates possibilities that the accused person is without guilt and is actually innocent of the allegations.
Although an alternate theory may exist and would infer that the accused lacks guilt of the allegations, the alternative theory presented must be logical and rational and present as a reasonable possibility. Indeed, for a reasonable doubt to arise, the doubt must be reasonable rather than based on a far fetched and unlikely scenario as an alternate theory. This requirement that reasonable doubt be based upon logical and rational inferences and reasonable possibilities was articulated by the Supreme Court of Canada within the cases of R. v. Lifchus, 1997 CanLII 319 (SCC),  3 S.C.R. 320 and R. v. Villaroman, 2016 SCC 33 (CanLII),  1 S.C.R. 1000, which cited Lifchus, and wherein such cases it was said:
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.
Accordingly, whereas reasonable doubt may arise from logical and rational inferences, the prosecution is without a need to negate far fetched conjecture or outrageous speculation. A reasonable doubt may be established only by presenting reasonable possibilities as an alternate theory. 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.
Establishing a reasonable doubt based on logical and rational inferences to show the reasonable possibility that the accused is innocent of the allegations being prosecuted is an excellent defence strategy; however, for a reasonable doubt, the doubt must be reasonable in that the alternate theories presented involve reasonable possibilities that are sensibly inline with the evidence for the facts in the case.