Ottawa -- After being used in Canada for almost 30 years, the Supreme Court imposed a ban yesterday on witness testimony obtained under hypnosis, ruling it is not scientifically reliable enough to have a place in a court of law.
Canada is believed to be the first country to impose a blanket prohibition, although other countries place restrictions on witnesses who recall memories while being hypnotized.
The 6-3 ruling was a victory for Stephen Trochym, a Canada Post worker from Toronto who was convicted 12 years ago of the second-degree murder of his girlfriend, Donna Hunter, in 1992.
The Supreme Court threw out the verdict and ordered a new trial, concluding that the testimony of a neighbour, who recalled under hypnosis she had seen Mr. Trochym at Ms. Hunter's apartment in the hours following the murder, was too unreliable to be admitted in court.
"This technique and its impact on human memory are not understood well enough ?. to be sufficiently reliable to be used in a court of l aw," Justice Marie Deschamps wrote for the majority. "Although hypnosis has been the subject of numerous studies, these studies are either inconclusive or draw attention to the fact that hypnosis can, in certain circumstances, result in the distortion of memory."
Judge Deschamps pointed out numerous potential problems, including the prospect of false memories, the possibility of a hypnotist influencing a subject and a tendency of witnesses to strongly believe what they remembered under hypnosis.
Judge Deschamps also noted that a number of public inquiries in recent years have highlighted the importance of guarding against wrongful convictions.
The ruling sounds a "death knell" to a controversial technique that has been under growing scrutiny as the court system seeks to eliminate pseudo-science, said David Paciocco, a criminal law expert at the University of Ottawa.
"There's been a knock on hypnosis. It looks like a pseudo-science that does not have the consistency of result you'd like to have in a legal system," he said.
"We don't allow evidence of polygraph results to be put into court because they're just too dangerous ? and many people felt we should be taking a similar approach to hypnotized evidence."
Mr. Paciocco said hypnosis enhanced testimony is not routinely used in Canada "but it's not rare enough to make this decision unimportant."
The saga of Robert Baltovich is one of Canada's best-known cases involving hypnotically enhanced testimony.
Two years ago, the Ontario Court of Appeal ordered a new trial for the Toronto man, who had spent eight years in jail for the 1990 killing of his girlfriend, a University of Toronto student whose body has never been found.
The appeal court said the trial judge failed to warn jurors about the reliability of hypnotically enhanced eyewitness testimony.
Lawyer James Lockyer, who represented Mr. Trochym and Mr. Baltovich, called the ruling "a great relief " because it effectively bars evidence that judges and juries just cannot trust.
"The reality is that hypnosis is more than capable of generating completely unreliable evidence."