The Ontario Court of Appeal has stressed the importance of fairness for those accused of sexual assault, in a case in which the complainant could not identify her assailant and the DNA evidence was inconclusive – even about whether any assault had happened. A man had been convicted of sexually assaulting the woman and sentenced to 18 months in jail. The appeal court ordered a new trial.

The case, called the Queen and J.S., comes amid a raging debate over whether the criminal process provides justice for sexual-assault victims. It is the latest of several, in Ontario and elsewhere, in which courts have thrown out convictions and ordered new trials after finding basic principles of justice had not been met. And, as with some high-profile cases of the past year, it involved severe intoxication, although not the issue of consent.

It was "a weak case," the two-women, one-man appeal court said in a ruling released on Monday. "There was little independent evidence, forensic or otherwise, that sexual intercourse had taken place." The prosecution misstated forensic evidence, a misstatement not corrected by Ontario Superior Court Justice Robert Scott in his address to the jury, Justice Lois Roberts said in her ruling, joined by Justice Janet Simmons and Justice Paul Rouleau.

Story continues below advertisement

"There is always the risk that a jury may treat forensic evidence as infallible because of its scientific nature and, as a result, overemphasize its significance," the court said. "It is therefore very important that forensic evidence is carefully and accurately explained."

The complainant told a 2013 trial that she could not remember "98 per cent" of the events on the evening in question. She had been drinking and while she could vaguely remember being at a bar, could not remember a second bar she had visited with friends. Ultimately, she passed out and was carried to a bed and left beneath the covers with her clothes on during a party in a house in June, 2010.

In the middle of the night, she woke up briefly because, she said, she felt that someone was having intercourse with her. She heard spitting, she said. The next time she woke, she said, her skirt was pushed up and she was not wearing her underwear. She described a silhouette in vague terms. It did not fit the man who was ultimately charged – a man she knew and therefore, in the eyes of the appeal court, might well have recognized, thus weakening the case.

She went to hospital later that day, but no evidence of sexual intercourse was found. Some of the men at the party, including the man ultimately accused, underwent DNA tests. Trace amounts of DNA of at least two different men, including her boyfriend, was found on the complainant's underwear. The DNA of the accused man was a possible, although not certain, match for one of these DNA profiles.

The accused said in court that after the complainant began yelling at 5 a.m., he came into the room from his room across the hall and, when she asked about her underwear, he had found them on the floor and picked them up. He told the court he had been biting his nails, which explained why his DNA might have been on the underwear. He also said his girlfriend was standing in the doorway at the time and she testified that that was true.

The prosecutor said the accused had invented this explanation – "the fatal flaw," she called it – to fit with the forensic evidence disclosed to him. If it had been the truth, she said, he would have told the police during his initial interview.

But the appeal court said that he had the right to silence when speaking with the police and that the prosecution's fatal-flaw comment "amounted to an impermissible invitation to the jury to use disbelief of that evidence as evidence of guilt." (The prosecution needs to prove its case; the defendant is not required to prove innocence and may be found not guilty even if not believed.)

Story continues below advertisement

If the guilty verdict had not been thrown out, "This case would have amounted to a miscarriage of justice," Toronto criminal-defence lawyer Joseph Neuberger, who was not involved, told The Globe and Mail. "It's extremely important that we adhere to the principles that have come into play over many, many years," such as proof beyond a reasonable doubt.

The Ontario Court of Appeal threw out a sexual-assault conviction in a case in August, citing an overemphasis on believing the complainant, and thus making the accused prove his innocence. Alberta's Court of Appeal made a similar ruling in December of 2016.