Testifying is an unnerving experience for most people. This stress can increase the natural human tendency to forget things that are in fact stored in the human memory. A memory, however, can be jarred in a
number of ways. "[A] song, a scent, a photograph, an allusion, even a past statement known to be false" can revive a memory.56More commonly, written statements believed to record facts accurately are relied upon to refresh a faded memory. The law enables counsel, subject to limits, to attempt to refresh the memory of a witness.
Witnesses are generally free to use whatever means they choose to refresh their memories prior to trial, although the means used can affect the weight that is given to their evidence. By way of exception, testimony, such as post-hypnosis evidence (testimony on a matter about which the witness’s memory has been refreshed using hypnosis) that has been generated using unproven "scientific" memory enhancing techniques is prima facie inadmissible. Before such testimony can be received, the party presenting it will be obliged to demonstrate that the relevant technique possesses the threshold of reliability required for "novel science" in the expert opinion evidence context.
As a general rule, witnesses are free to use whatever means they choose to refresh their memories, although the means used can affect the weight the evidence is given. 57 Opposing counsel is therefore entitled to explore what means, if any, were undertaken to refresh a witness’s memory prior to trial. Where documents or real items have been consulted, the trial judge has discretion to order them to be produced to opposing counsel. 58As an exception to this general rule, post-hypnosis evidence (testimony on a matter about which the witness’s memory has been refreshed using hypnosis) is prima facie inadmissible because currently post-hypnosis evidence does not have the kind of "reliable foundation" needed for
"novel science." The Court arrived at this view in R. v. Trochym59because the impact of hypnosis on human memory is not well understood. The prevailing current view is that "hypnosis makes people more suggestible [and] that any increase in accurate memories during hypnosis is accompanied by an increase in inaccurate memories [and] that hypnosis may compromise the subject’s ability to distinguish memory from imagination, and that subjects frequently report being more certain of the content of post-hypnosis memories, regardless of their accuracy."60This makes witnesses who have had their testimony hypnotically refreshed more difficult to cross-examine, and gives their evidence a dangerous allure of confidence. As a result, it has been held that post-hypnosis evidence is to be excluded absent proof by the party who is seeking to rely on it of a change in the underlying scientific assumptions about its reliability. The witness may testify on those matters on which their memory has not been refreshed by hypnosis provided the probative value of that testimony outweighs the potential prejudicial effect of the hypnosis, including its potential tainting impact on topics that are not touched, and the extent to which the exclusion of hypnotically induced memories will impair cross-examination on other matters. Where such evidence is admitted, the judge must warn the jury of the potential frailties of post-hypnosis evidence and give proper instructions on the weight of the testimony.61Prior to Trochym some courts had admitted the testimony of witnesses who have been injected with sodium amytol, a supposed "truth serum,"62in an effort to improve their memories. It is now clear that before testimony secured using this or any other "scientific" memory enhancing technique is admitted, the party presenting the proof will be obliged to demonstrate that the technique possesses the threshold reliability required of novel science.
Past Recollection Recorded
A witness may, with leave of the court, refresh her memory in court from a document or an electronic record that was recorded reliably. The witness must use the original, if it is available, but where it is not,
an authenticated copy can be relied on. If the record is a document created by the witness, it must have been created at a time when the memory of the witness was sufficiently fresh to be vivid and probably accurate. If the record is a document created by another, or an electronic recording, that document or recording must have been reviewed by the witness at a time when his memory was sufficiently fresh to be vivid and probably accurate. The witness can rely on the document or electronic record to assist in presenting his testimony only if the witness is able to assert that the document or recording accurately represents his recollection at the time it was made.
Present Recollection Revived
Subject to an exclusionary discretion where doing so would be too suggestive, a witness may consult any document while testifying. As long as the document sparks an actual recollection of the event recorded, the witness can present oral testimony about the event remembered.
Transcripts and Depositions
A court may allow witnesses who cannot recall matters they have previously testified about to be shown transcripts of their earlier testimony or their depositions. There is no contemporaneity requirement, nor is there a need for the witness to have read over the transcript and to have verified that it accurately recorded her testimony.
As described above, questions alluding to events may stimulate the memory of a witness. Or counsel may even obtain leave to ask leading questions of her witness when the memory cannot otherwise be stimulated and it is in the interests of justice to permit such questions. Most often, documents will be relied upon.
Provided certain prerequisites are met, a rule generally known as "past recollection recorded" permits witnesses to use, in court, documents (such as business records, or memoranda of events) or electronic recordings,63to assist them while giving their testimony. "The admission of past recollection recorded is an exceptional procedure and the conditions precedent to its reception should be clearly satisfied."64First, this rule should not be used to permit a witness to use any document or electronic recording unless the witness actually needs to
have his memory refreshed. In R. v. McCarroll the fact that the witness was obviously lying when asserting memory problems prevented the Crown from showing the witness their prior statement. This is sensible.65The refreshing memory rules are intended to facilitate the supply of testimony that would otherwise be unavailable, not to bolster the testimony witnesses are able to give in any event or to give them a script for their testimony. Nor should this rule be used to enable a party to control the evidence his witness will supply. In R. v. Rose the Crown presented a Crown witness with her written statement as soon as she took the stand and tried to use the record as a script for the testimony. This was inappropriate, and amounted to improperly leading the witness.66Relying on Wigmore on Evidence, the Supreme Court of Canada has described the prerequisites that apply where the witness does require to have their memory refreshed, and the doctrine of "past recollection recorded" is relied on:
1) The past recollection must have been recorded in some reliable way.
2) At the time [he made or reviewed the record, his memory] must have been sufficiently fresh and vivid to be probably accurate.673) The witness must be able now to assert that the record accurately represented his knowledge and recollection at the time [he reviewed it]. The usual phrase requires the witness to affirm that he "knew it to be true at the time."
4) The original record itself must be used, if it is procurable.68
Each requirement is important. In R. v. Wilks69the Manitoba Court of Appeal overturned a verdict because the trial judge permitted a witness to rely on a trial summary he had prepared from pre-existing computer records, without attesting that the trial summary accurately recorded his knowledge at the time of the events recorded. And in R. v. Fliss the trial...