Canadian Criminal Evidence/Standard of Proof

General Principles
The standard of proof asks to how convinced the trier of fact must be of something. Canadian criminal law has three core standards:
 * 1) Proof beyond a reasonable doubt which is the standard to be met by the Crown against the accused;
 * 2) 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;
 * 3) 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.

Balance of Probabilities
The "balance of probabilities" is described as being "more probable 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 is used in civil trial cases.

It is also the standard of proof used in administrative law cases and disciplinary cases in more professions in Canada.

Beyond a Reasonable Doubt (BARD)
The standard of "beyond a reasonable doubt" (BARD) is a common law standard of proof in criminal matters. This standard is exclusively used in criminal or quasi-criminal proceedings. This includes not only adult criminal trials, but also young offender cases, adult sentencing, and certain provincial penal offences.

The standard of "reasonable doubt" consists of a doubt based on reason and common sense which must be logically based upon the evidence or lack of evidence. It is not based on "sympathy or prejudice".

Proof beyond a reasonable doubt "it does not involve proof to an absolute certainty; it is not proof beyond any doubt nor is it an imaginary or frivolous doubt."

However, belief that the accused is "probably guilty" is not sufficient and must acquit.

The standard as the ultimate burden of proof is "inextricably intertwined with that principle fundamental to all criminal trials, the presumption of innocence". The burden should never shift to the accused.

The burden of proof placed upon the Crown lies “much closer to absolute certainty than to a balance of probabilities.” The standard is more "than proof that the accused is probably guilty" in which case the judge must acquit.

“[A] reasonable doubt does not need to be based on the evidence; it may arise from an absence of evidence or a simple failure of the evidence to persuade the trier of fact to the requisite level of beyond reasonable doubt.”

The standard of BARD only applies to the evaluation of the evidence as a whole and not individual aspects of the evidence.

Reasonable doubt must come as a rational conclusion from the evidence available and not as a basis of conjecture.

Where the issue is the reliability or credibility of a witness, the courts must generally consider corroborative evidence.

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), [1977] 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 evidence, if believed, could reasonably support an inference of guilt."

Legal Proof
Frequently seen standards of proof that are seen include:
 * 1) "air of reality" / prima facie case
 * 2) reasonable and probable grounds / reasonably-based probability
 * 3) reasonable suspicion

Air of Reality Test
The air of reality test determines whether a particular legal defence should be considered by the trier-of-fact. When the standard is met, the effect is to add a burden upon the Crown to prove that the defence fails beyond a reasonable doubt.

In the context of a jury trial, the test determines whether the judge will give instructions to the jury that they should consider the particular defenses. .

The air of reality test creates a burden of evidence, not a persuasive burden.

The test applies to all defences as well as all elements of each defence.

The jury should be instructed of defences that have evidence supporting it. By inference, a "judge has a positive duty to keep from the jury defences lacking an evidential foundation". There must be evidence to support each element of the defence.

The test requires that there must be "some evidence" upon which "a properly instructed jury acting reasonably could base an acquittal".

The decision of a judge on the air of reality test may be reviewed as a "question of law" on a standard of "correctness".

The judge should not consider credibility, make findings of fact, draw inferences, or "weigh" the evidence. He or she should not consider the likelihood of success of the defence.

The judge must consider whether inferences would be necessary for the defence to succeed and whether those inferences from the evidence are reasonable.