Burden of Proof
The burden of proof indicates who has the responsibility or onus to prove something.
Generally, there are three types of burdens. First, there is the "burden of persuasion" (often called a "legal burden", "primary burden", or "major burden"), which is the requirement to prove the case or disprove the defence. Failure to discharge this burden results in the party losing the case. This type of evidence typically is said to impose a "onus of proof". Second, there is the ""evidential burden" (often called the "secondary burden", "burden of going forward", or "minor burden"), which is the requirement of putting an issue before the court using the available evidence. Finally, there is a "tactical burden", which is not a legal standard, but rather is descriptive of the strength of opposing counsel's case and the implication of what is needed to overcome it.
Waiver of Burden for Admissibility
Opposing counsel may waive any requirements of proof that would necessitate a voir dire. There is "[n]o particular words or formula" that need to be utter "to express the waiver and admission. All that is necessary is that the trial Judge be satisfied that counsel understand the matter and has made an informed decision".
Burden of Persuasion
A "persuasive burden" is a legal question that asks "how the issue should be decided".
Burden Upon the Accused
Section 11(d) of the Charter allocates the burden of persuasion upon the Crown at all times. The section states:
Proceedings in criminal and penal matters
11. Any person charged with an offence has the right
(d) to be presumed innocent until proven guilty according to law in a fair and public hearing by an independent and impartial tribunal;
- R v Fontaine,  1 SCR 702, 2004 SCC 27 (CanLII), per Fish J, at para 11
An evidential burden is not technically a "burden of proof". Nor is is a legal question. Rather it is a question of fact. It is the burden to determine "whether an issue should be left to the trier of fact".
In determining if the evidential burden is satisfied the judge must not "evaluate the quality, weight or reliability of the evidence".
A tactical burden is not a term of law, but rather is descriptive of the nature of the opposing counsel's case. A tactical burden exists where the Crown has established a prima facie case such at in order to raise a doubt the defence may need to respond by calling evidence.
This "burden" does not offend the right to a presumption of innocence under s. 11(d) of the Charter.
"Might Reasonably Be True" Test
The "might reasonably be true" test arises from the doctrine of recent possession which is based on the premise that the accused risks conviction for certain offences "unless he or she furnishes a plausible explanation".
The "might reasonably be true" test should not be applied in credibility cases "dealing with contradictory evidence...where the presumption of innocence, and none other, applies." The test amounts to "imposing an affirmative obligation on the defence to either introduce evidence disproving guilt...and undermines the presumption of innocence"
R v Rattray, 2007 ONCA 164 (CanLII), at para 14
Rattray, ibid., at para 13
Presumption of Innocence
It is well established at common law that all persons are entitled to the legal presumption of innocence for all charges they are not convicted for.
The Charter also affirms this burden in s. 11(d):
11. Any person charged with an offence has the right...
- (d) to be presumed innocent until proven guilty according to the law in a fair and public hearing by an independent and impartial tribunal;
An ancillary principle to this right, the Crown must also make out a prima facie case before the accused must respond.
Therefore the Crown has the burden of proving all the elements of the offence. The onus of proving guilt never switches from the Crown to the accused.The “accused bears no burden to explain why his accuser made the allegations against him”
Woolmington v Director of Public Prosecutions,  AC 462
R v Appleby,  SCR 303, 1971 CanLII 4 (SCC)
R v Proudlock, 1978 CanLII 15 (SCC),  1 SCR 525 at para 6
R v Manchuk,  SCR 341, 1938 CanLII 6 (SCC), at p. 349
R v Dubois,  2 SCR 350, 1985 CanLII 10 (SCC), at pp. 357 to 258
- R v Lauer, 2011 PECA 5 (CanLII) at para 73
- see R v Briand, 2010 NLCA 44 (CanLII), (2010), 258 CCC (3d) 416 (N.L.C.A.)
- see R v J.C.H., 2011 NLCA 8 (CanLII) at para 18