Credibility and Reliability of Child Witnesses
There is no fixed formula for dealing with child witnesses.
Credibility of children are approached generally in the same way as adults. However, the standard of a "reasonable adult" may not be appropriate as a “reasonable child” may differ from that of an adult. "Flaws, such as contradictions, in the testimony of a child may not toll so heavily against credibility and reliability as equivalent flaws in the testimony of an adult." A child should not be held to the same "exacting standards" as an adult. The evidence of a child must be approached on a "common sense" basis, "taking into account the strengths and weaknesses which characterize the evidence". 
Children "experience the world differently from adults", as such absence of details such as time and place are understandable and not necessarily fatal.Stereotypes of children should be avoided.
Regardless, the standard of proof for the Crown is always the same and should be examined with the same level of scrutiny.
For details on the appropriate approach to assessing the evidence of children, see R v B.G. 1990 CanLII 114 (SCC),  2 SCR 30 and R v W. (R.), supra
In certain cases, guilt can be found upon the testimony of a single child witness without corroboration.
Guilt may also be found despite the presence of inconsistencies on material issues, lack of recent complaint, motive to lie and concoct, passage of time, and recovered memory.
The passage of a significant amount of time between the events and the laying of charges does not by itself warrant any caution.
It is recognized that a child "will have a better recollection of events shortly after they occurred" than weeks or months after.
The mere fact of a significant passage of time between the alleged offences and the laying of the charges does not, in itself, mandate such a caution.
Helpful guidelines were suggested in R v A.F. 2007 BCPC 345:
- the credibility of child witnesses must be assessed carefully (in this context, “carefully” implies no bias either towards accepting or rejecting that evidence);
- the standard to be applied in assessing the credibility of a child witness is not necessarily the same as that applied to a reasonable adult;
- allowance must be made for the fact that young children may not be able to recount precise details and may not be able to communicate precisely the “when” and the “where” of an event, but their inability to do so should not lead to the conclusion that they have misperceived what has happened to them or who has done something to them;
- there is no assumption or presumption at law that a child’s evidence is less reliable than an adult’s;
- a common sense approach must be used in assessing the credibility of a child’s evidence, having regard to the age of the child, the child’s mental development and the child’s ability to communicate;
- inconsistencies, particularly concerning peripheral matters such as time or place, should not have the same adverse effect on the credibility of a child as it might in the case of an adult, having regard to the age and mental development of the child and other relevant factors;
- the burden of proof (guilt beyond a reasonable doubt) remains unchanged when the Crown case is founded upon the evidence of a child or children. Specifically, the rules pertaining to credibility as set out by the Supreme Court of Canada in R v D.W. do not change just because the Crown’s case is founded upon such evidence.
There can be no assumption that a witness is unreliable simply because of their age. However, where the age is particularly young, such as where a 6 year old is testifying to a time when he was under 2 years old, then special considerations should be made.
- R v Marquard, 1993 CanLII 37 (SCC),  4 SCR 223
R v B (G), 1990 CanLII 114 (SCC),  2 SCR 30 per McLachlin J. at para 48
R v H.C. 2009 ONCA 56 (CanLII), (2009), 241 CCC (3d) 45 at para 42
- R v H.C. at para 42
R v B (G) at para 48
- R v W. (R.), 1992 CanLII 56 (SCC),  2 SCR 122
R v W. (R.) at para 24
R v R.R.D., 2011 NLTD(G) 78
R v B.E.M.,  BCJ No. 2787 (C.A.)
R v B (G) at para 48
R v W. (R.) at para 25 (the approach to child evidence does "not mean that the evidence of children should not be subject to the same standard of proof as the evidence of adult witnesses in criminal cases.")
R v Marquard (1993), 85 CCC (3d) 193 (S.C.C.) at pp. 221-222
R v W.S. (1994), 90 CCC (3d) 242 (Ont. C.A.) at p. 251
R v P.B.,  O.J. No. 423 (S.C.J.)
R v T.P., 2010 CanLII 79501 (NL PC),  N.J. No. 414 (P.C.)
- R v Vetrovec, 1982 CanLII 20 (SCC),  1 SCR 811 ("The common law, rejecting the 'numerical criterion' common to some legal systems, has traditionally held that the testimony of a single witness is a sufficient basis for a criminal conviction.")
- R v François, 1994 CanLII 52 (SCC),  2 SCR 827
- R v Betker, 1997 CanLII 1902 (ON CA) - adult testifying to abuse as child
- R v F. (C.C.), 1997 CanLII 306 (SCC),  3 SCR 1183, at para 19 ("It is self‑evident to every observant parent and to all who have worked closely with young people that children, even more than adults, will have a better recollection of events shortly after they occurred than they will some weeks, months or years later.")
- R v V. K., 1991 CanLII 5761 (BC CA) at para 18, 33
R v F.(C.), 1996 CanLII 623 (ON CA) at para 18
The accuracy of memories of children may be affected adversely by the use of therapy. Prudence must be taken in accepting recovered memories.