The SCC has ruled inadmissible testimony from witnesses who have been subjected to hypnosis. So holds the recently released R. v. Trochym. The ruling is somewhat unusual; it's not often that the Court issues a blanket condemnation of evidence that has been used in Canadian courts for many years. On the other hand, the outcome is generally a sensible one, given the dangers that hypnotically "aided" testimony can present. What research has has been done suggests that hypnosis can result in a fuller memory of events, but that the fuller memory may include false ones. And it's often impossible to tell the true from the false parts of the "enhanced" memory. Another danger is that the witness who has undergone hypnosis may come to view her post-hypnosis memories as completely accurate, regardless of whether such is the case. Cross-examining a witness who firmly (but mistakenly) believes that she is telling the truth presents great difficulties for the Defence, and these types of witnesses can carry great wieght with the jury.
Criminalreview has nicely explained Trochym and some of its implications for hypnosis as a forensic tool. I want to touch on another area where we may feel welcome fallout from the judgement - the admissibility of eyewitness testimony.
My pitch here is that Defence counsel can use Trochym to fight against eyewitness testimony that has been undermined by faulty post-event police conduct.
First off, one of the remarkable things about Trochym is that the SCC uses the Mohan/JLJ test to screen evidence other than expert opinion. Granted, the evidence in question has been impacted by the intervention of a so-called expert, but the fact remains that the Court has shown itself willing to exclude lay evidence using the expert evidence test.
Is the intervention of a hypnotist any different from the role of police in eliciting and recording eyewitness evidence? Although the police are not 'experts" in the elicitation of eyewitness identification, I would say not. The police elicitation process often plays a substantial role in determining what the witness says in her testimony. Much research has shown that bad lineup/photo array procedures can dramatically increase the prospects of a mistaken identification, which hardens and is repeated with great confidence by the witness at trial. Very often the police elicitation process and the witness' responses are led in evidence as well.
You may notice that the problems with eyewitness identification are similar to those that led to the demise of hypnotically "aided" testimony. Yet, ironically, proponents of hypnosis as a legitimate forensic tool have long-used this similarity in support of admissibility. The argument is simple: "Courts don't exclude eyewitness testimony even though it can exhibit the same potential weaknesses, instead leaving the issue of reliability to the good sense of the jurors. The courts should treat testimony that follows hypnosis in the same way."
This pitch worked with many courts for many years. But it has worn thin in the U.S., where about half of the states now exclude post-hypnosis testimony. The SCC in Trochym took the same approach. And in doing so, it turned this reliance on eyewitness testimony back on the proponents of hypnosis. The Court's argument ran as follows. Our knowledge of science, and the reliability of evidence, necessarily changes over time. Eyewitness testimony is an area where improved knowledge reveals that there have been mistaken eyewitness identifications leading to wrongful convictions. Courts have thus all but excluded in-dock identification as unreliable. More than this, the Sophonow Inquiry Report has recognized that triers of fact are often duped by unreliable evidence presented by certain and sincere witnesses, and has recommended systemic changes to reduce the likelihood of this happening. "While Justice Cory was specifically addressing ordinary memory, his recommendations make it all the more clear why a technique used to enhance memory must be approached with great caution" (para. 46, emphasis in original).
In effect, the Court is saying that the hypnosis proponents can't rely on the same weaknesses in eyewitness testimony as a justification for admissibility, because our system now recognizes that those weaknesses present a great danger of wrongful convictions. The affirmative reference to the Sophonow Report is not the first that we've seen from the Court, but it surely adds fuel to the argument that police processes that taint the reliability of eyewitness evidence can in the proper case provide a sound basis for exclusion.
This argument for the exclusion of unreliable eyewitness evidence is not novel. A number of other cases provide support. But Trochym is a decision of the SCC, and it uses the bad eyewitness evidence scenario as justification for the blanket exclusion of post-hypnosis testimony. It's just a matter of time before Defence lawyers use Trochym to attack bad police processes in eliciting eyewitness testimony. In my view, they may enjoy unprecedented success in doing so. A few successful attacks may be the final push that convinces all Canadian police forces to adopt the sensible and straight-forward Sophonow Report proposals aimed at limiting the risk of mistaken eyetwitness testimony leading to a wrongful conviction.
