R. v. Wanihadie, 2021 ABCA 173, at paragraphs 10 and 11:
Absent an express waiver or consent among the parties, when the Crown seeks to tender evidence from witnesses who purport to identify the accused by viewing videotapes, without any firsthand knowledge or direct observations of the offence, a voir dire should be held.
The fundamental purpose of a voir dire is to determine the admissibility of disputed evidence. This is distinct from assessing the merits of the case on consideration of all of the admissible evidence…A voir dire is the forum to explore the length of the prior relationship between the witness and the accused, the circumstances of the prior relationship and the recency of the contact between the witness and the accused prior to the incident recorded…This is to determine whether the recognition witness is indeed “a helpful witness who is in a better position than the trier of fact to identify the accused”: Knife at para 9. It permits the accused to test the proposed recognition evidence without limitations or evidentiary constraints and ensures the integrity of the trial process.