Standard of Proof
The standard of proof asks to how convinced the trier of fact must be of some something. Canadian criminal law has three core standards:
- Proof beyond a reasonable doubt which is the standard to be met by the Crown against the accused;
- a balance of probabilities or Proof on a preponderance of the evidence which is the burden of proof on the accused when he has to meet a presumption requiring him to establish or to prove a fact or an excuse;
- Evidence raising a reasonable doubt which is what is required to overcome any other presumption of fact or of law. Once a prima facie case has been established by the evidence of the crown, there is no need to prove innocence. Rather the accused need only raise a doubt in the evidence.
The US has a fourth standard known as "clear and convincing evidence" which is a middle ground between the two standards, however, this has never been officially adopted in Canada. When a proposition at issue in a case, such as an element of an offence, must be proven, the standard must be reached using the weight of the totality of evidence presented, not on each individual piece of evidence .
When weighing evidence against any standard of proof, the general rule of totality will govern. Each piece of evidence or each fact cannot be considered in isolation to establish a fact. They must be considered in the context as a whole. This principle is central to consideration of Circumstantial Evidence.
Balance of Probabilities
The "balance of probabilities" is described as being "more probable than not", "more likely than not", or more technically, the chance of the proposition being true is more than 50%. This standard is known as the civil standard as it exclusively used in civil trial cases.
Generally, where there are factual questions that are preconditions to the admissibility of evidence should be on a standard of balance of probabilities. This standard should only be increased "in those certainly rare occasions when the admission of the evidence may itself have a conclusive effect with respect to guilt".
Continental Insurance Co. v Dalton Cartage Co., 1982 CanLII 13 (SCC),  1 SCR 164 - SCC rejected a variable standard, adopting only balance of probabilities
F.H. v McDougall, 2008 SCC 53 (CanLII) at para 49
R v Evans, 1993 CanLII 86 (SCC),  3 SCR 653
- R v Arp, 1998 CanLII 769 (SCC),  3 S.C.R. 339,  S.C.J. No. 82, per Cory J.
Beyond a Reasonable Doubt
Sufficiency of Proof
Before any evidence gets to a trier of fact there is often a requirement to discharge an evidential burden for the trier of law (i.e. the judge).
In a preliminary inquiry the Crown must show on the whole that the evidence they will present is sufficient to potentially convict the accused. The purpose of this initial evaluation is to avoid frivolous suiting being brought in that have no chance at success.
The leading case for the standard of proof needed before evidence can be put to the jury is United States of America v Shephard, 1976 CanLII 8 (SCC),  2 SCR 1067. The Court held that:
- [The] which governs a trial Judge in decideing whether the evidence is sufficient to justify him in withdrawing the case from the jury, and this is to be determined according to whether or not there is any evidence upon which a reasonable jury properly instructed could return a verdict of guilt.
In a case where some of the evidence the Crown is relying upon is not directly to the issue of the case, the Crown must satisfy the judge that "the evidnece, if believed, could reasonably support an inference of guilt."
- R.v. Arcuri, SCC 54 (CanLII),  2 SCR 828
Frequently seen standards of proof that are seen include:
- "air of reality" / prima facie case
- reasonable and probable grounds / reasonably-based probability
- reasonable suspicion