When considering a prior inconsistent statment the court must begin by presuming that the statment is inadmissible for the truth of its contents unless it has been estliabhsd there is sufficient indicia of trustworthiness.
Even when the hearsay evidence is reliable and necessary, there is still a discretionary ability to exclude the evidence where the prejudicial effect outweighs the probative value.
- R v Khan, at para. 29
- R v Khan, at para 30
- R. v. Blackman, 2008 SCC 37
- R v Underwood 2002 ABCA 310 at para 19
- R v Starr, 2000 SCC 40 at para. 212-214
- R v Smith at para 45
R. v. Woodard, 2009 MBCA 42 summarized procedure for the admission of evidence under the principled approach to hearsay as follows at 46:
(1) The first matter to determine before embarking on a hearsay admissibility inquiry is whether the proposed evidence is hearsay. An out-of-court statement will be hearsay when: (1) it is adduced to prove the truth of its contents (the purpose); and (2) there is limited or no opportunity for a contemporaneous cross-examination of the declarant (the concern) (see Khelawon, at paras. 56-58).
(2) Once the proposed evidence is identified as hearsay, it is presumptively inadmissible, unless it falls under a traditional common law exception to the hearsay rule or is admitted under the principled approach to the hearsay rule (see Khelawon, at paras. 56, 59, and Couture, at para. 78).
(3) Whether the hearsay meets the necessity and threshold reliability criteria under the principled approach will be determined on a voir dire. The onus is on the person who seeks to adduce the evidence to establish these criteria on a balance of probabilities (see Khelawon, at para. 47).
(4) If the proponent of the evidence cannot meet the twin criteria of necessity and reliability, the general exclusionary rule prevails. The trial judge's function (as gatekeeper) is to guard against the admission of hearsay evidence which is unnecessary in the context of the issue to be decided, or the reliability of which is neither readily apparent from the trustworthiness of its contents, nor capable of being meaningfully tested by the ultimate trier of fact (see Khelawon, at paras. 2-3).
(5) The criterion of necessity is founded on society's interest in getting at the truth and is intended to ensure that the evidence presented to the court be in the best available form, usually by calling the maker of the statement as a witness. If that is not possible, it may be that if the evidence is to be adduced at all, it can only be presented in its hearsay form (see Khelawon, at para. 49, and Couture, at para. 79).
(6) The criterion of threshold reliability is about ensuring the integrity of the trial process and is usually met: (1) by showing that sufficient trust can be put in the truth and accuracy of the statements because of the way in which they came about; or (2) by showing that, in the circumstances, the ultimate trier of fact will be in a position to sufficiently assess their worth. The two ways of demonstrating threshold reliability are not mutually exclusive. In cases where the declarant is available to be cross-examined, the focus will necessarily be on the latter way (see Khelawon, at paras. 49, 61-63, Couture, at para. 80, Devine, at para. 23, and Blackman, at para. 35).
(7) A distinction must be made between "ultimate reliability" and "threshold reliability." Only the latter is inquired into on the admissibility voir dire. The failure to respect this distinction would not only result in the undue prolongation of admissibility hearings, it would distort the fact-finding process. Whether the evidence is relied upon to decide the issues in the case is a matter reserved for the ultimate trier of fact to decide in the context of the entirety of the evidence (see Khelawon, at paras. 3, 50).
(8) Relevant factors to be considered cannot invariably be categorized as relating either to threshold or ultimate reliability. Rather, the relevance of any particular factor will depend on the particular dangers arising from the hearsay nature of the statement and the available means, if any, of overcoming them (see Khelawon, at para. 55).
(9) Although there are no hard and fast rules about the manner of conducting the hearsay admissibility inquiry, there are good reasons to look first at whether there are adequate substitutes that give the trier of fact a sufficient basis to assess the statement's truth and accuracy. Whenever the threshold reliability requirement is met on this basis, there is no need to inquire further into the likely truth of the statement (see Couture, at paras. 87-88).
(10) Even if the two criteria are met, the trial judge has the discretion to exclude hearsay evidence where its probative value is outweighed by its prejudicial effect (see Khelawon, at para. 49).
A KGB application is typically one made by the Crown, but may also be made by the defence. The defence is permitted to apply to put a previous inconsistent statement into evidence for the truth of its contents.
Before a KGB application can be undertaken the court must first be satisfied on a threshold that the prior inconsistent statement is the sole evidence of the witness and that the statement is consistent with the evidence in court.
- See R. v. Brisco,  A.J. No. 208 and R. v. Eisenhauer,  S.C.C.A. No. 144
- R v KGB at para. 74
Necessity must be in relation to a particular goal. The court should consider whether that goal can be achieved by other evidence that would otherwise be more reliable. If the exists other avenues of proving the fact sought then the exception will not apply.
- see eg. R. v. Abel, 2011 NLTD 173 at 117
- See R. v. Devine, 2008 SCC 36 at para 16
R. v. U.(F.J.), 1995 CanLII 74 (SCC),  3 S.C.R. 764
see also R. v. De Elespp  A.J. No. 6702 at para 37 and 108
R v. Rombough  A.J. No 1768 at para. 36
R. v. Biscette  A.J. No. 557
R. v. Clarke (Ont. Ct. (Gen. Div.))  O.J. No. 997 at para F
- R v U(FJ)
Death of the witness is typically sufficient to establish necessity so long as the witness was the only source of information contained within the statement.
Witness refuses to testifyEdit
A witness who refuses to testify when all efforts to obtain that testimony have been taken to no avail will typically satisfy the requirement of necessity.  There is no onus on the Crown to prove why the complainant failed to testify.
- e.g. R v Taylor, 2012 ONCA 809
- R. v. Lavery,  B.C.J. No.2713 (S.C.), at para. 9;
R. v. C.C.B.,  S.J. No. 672 (P.C.), at paras. 5 - 9, and 23 - 31
R. v. Goodstoney, 2005 ABQB 128
R v Gardipy, 2012 SKCA 58 at 19
Where the experience testifying may be so traumatic at to prevent a chlid from testifying, the requirement of necessity will be satisfied.
While in some limited cases the court may have the child testify within the voir dire to support the reliability of the statment. More often, the statement will be admitted without oral evidence and the lack of cross examination will go to the weight of the prior statement.
- R. v. Rockey,  3 SCR 829 at 846;
- Sopinka, The Law of Evidence in Canada, 2nd edition, at ss.6.55
As always, the focus of analysis is to be on the hearsay dangers. The primary danger of concern is the inability to cross-examine. The court must be satisfied that the statement is sufficiently reliable to be considered as evidence. The judge must determine whether the statement shows sufficient reliability to afford a satisfactory basis for evaluating the truth of the statement. The criteria of reliability deals with threshold reliability, not ultimate reliability to establish some fact.
There are two manners in which relability can be established: 1) by detailing the circumstances in which the statement was taken; or 2) “by showing that, in all of the circumstances, the ultimate trier of fact will be in a position to sufficiently assess the worth of the statement.
Where the circumstances of the statement "substantially negates" the possibility that the declarant was untruthful or mistaken, then the statement is reliable.
- solemnity of the occasion
- the declarant’s adverse interest
- the declarant had particular means of knowledge of events described
- the statement distinguishes between first and second hand knowledge
- the statement was officially recorded and preserved
- the absence of a reason and/or motive to fabricate the statement (non-fabrication)
- the timing of the statement in relation to the event spoken of (contemporaneity/remoteness)
- the demeanour of the declarant at the time of the making of the statement (demeanour)
- the spontaneity of the statement (spontaneity)
- the relationship between the declarant and the witness (relationship)
- the detail given in the statement (detail);
- whether the declarant could be mistaken (mistake); 
- motive of the declarant (motive)
- conduct of declarant
- whether the statement was recorded and
- “other”, including an “accurate record” - because it is clear from the cases that the list of factors is not closed and others may be added as appropriate to the particular circumstance.
Factors not to be considered in determining threshold admissibility:
- reliability or credibility of the declarant;
- general reputation of the declarant for truthfulness;
- prior or subsequent statements, consistent or not; and
- In particular, the bar that Starr erected on the use of corroborative evidence in the threshold reliability assessment no longer applies. Instead of categorizing reliability factors into discreet, non-mutually exclusive threshold and ultimate stages, courts should now "adopt a more functional approach... and focus on the particular dangers raised by the hearsay evidence sought to be introduced and on those attributes or circumstances relied upon by the proponent to overcome those dangers". In effect, trial judges may now consider evidence going beyond the circumstances under which the statement was made at the threshold reliability stage, which includes corroborative and/or conflicting evidence.
A videotaped statement can often be admitted where the declarant is available for cross-examination as there are often sufficient tools to assess the weight of the statement. 
- Morehouse,  A.J. No. 12 2004 ABQB 97 at para. 53
R v Finta 1992 CanLII 2783 ONCA aff’d at  1 SCR 701
R v Nguyen 2001 ABCA 98
- Morehouse; Nguyen at 44, ibid
- Morehouse; Nguyen
- Morehouse; Nguyen, ibid
- Nguyen, ibid
- Nguyen, ibid
- R. v. Burke, 2010 ONSC 6530
- R. v. Goodstoney, 2005 ABQB 128 at para 18
- R. v. M.N.P., 2012 MBQB 70
Presence of an Oath, Affirmation or WarningEdit
Where there is no oath, other evidence may substitute for it. This may include evidence from which it can be inferred from when the statement was made, the apparent solemnity of the location and occasion of the statement, an understanding of the importance to tell the truth.
- R. v. Trieu 2005 CanLII 7884 (ON CA), (2005), 195 C.C.C. (3d) 373 (Ont. C.A.)
Opportunity for Cross-ExaminationEdit
The opportunity for Cross-examination "alone provides significant indications of reliability" and so could provide "an adequate assurance of threshold reliability to allow substantive admission of prior inconsistent statements"</ref>
The effectiveness of cross-examination as a sign of reliability "depends on the nature of of the recantation of the witness." So where there is a mere denial or absence of memory of the prior statement, cross-examination would have less importance.
- U(FJ) at p. 119
- R v H(S), 14 C.R. (5th) 80, 37 W.C.B. (2d) 362 citing R. v. Conway, 1997 CanLII 2726 (ON CA), (1997), 36 O.R. (3d) 579, 121 C.C.C. (3d) 397 and R. v. Tat (1997), 117 C.C.C. (3d) 481 (Ont. C.A.)
It is important to remember that "repeating a story to others doesn't make it reliable".
- R v H(S), (1998) 14 C.R. (5th) 80, 37 W.C.B. (2d) 362 at para. 32
Special Types of WitnessesEdit
Elderly or infirm witnesses are classes of witnesses who present risk of being deceased by the time a trial comes about.
For both of them their reliability can be established with evidence of their fitness at the time the statement was given, such as:
- medical evidence of any psychological reports regarding capacity
- any prescriptions being taken as well as their effect upon their capacity.
- R v Taylor 2012 ONCA 809 at para. 11
- Taylor at para. 10