Opportunity is the sine qua non of crime.
Evidence which shows or tends to show that an accused was present at or near a place at or near the time an offence was committed is relevant, material and prima facie admissible.
R. v. Doodnaught, 2017 ONCA 781, at para. 67.
Where conduct occurs and the Crown alleges that a particular person did it personally, not through an agent or some other instrumentality, the person’s physical presence, within the proper range of time and place, is an item of circumstantial evidence that enhances the likelihood that the person with that opportunity – the accused – committed the offence.
R. v. Doodnaught, at para. 66.
However, evidence of bare opportunity to commit an offence is not, without more, sufficient to establish the guilt of an accused beyond a reasonable doubt.
R. v. Yebes, 1987 CanLII 17 (SCC),  2 S.C.R. 168.
Evidence of opportunity, insufficient on its own to establish guilt beyond reasonable doubt, may have a different complexion placed upon on it by other evidence, as for example, evidence of skill, expertise, physical capacity, or possession of tools by which an offence was committed.
R. v. Doodnaught, at para. 69;
R. v. Davison (1974), 20 C.C.C. (2d) 424 (Ont. C.A.), at pp. 436-437;
R. v. Syms (1979), 47 C.C.C. (2d) 114 (Ont. C.A.), at p. 116.
Explaining away opportunity
It is always open to a party, such as an accused, to adduce evidence explaining away opportunity, such as by evidence of lack of physical capacity, or by evidence that tends to show the equivalent (or better) opportunity of others:
R. v. Minhas (1986), 29 C.C.C. (3d) 193 (Ont. C.A.), at p. 219;
R. v. Doodnaught, at para. 68.
Evidence of Exclusive Opportunity.
Evidence of exclusive opportunity, on its own, may be sufficient to prove the guilt of an accused beyond a reasonable doubt.
See, R. v. Imrich,  1 S.C.R. 622, affirming (1974), 21 C.C.C. (2d) 99 (Ont. C.A.).