TORONTO - It's a question that always seems to emerge whenever a Canadian court wrestles with a case of wrongful conviction: Why is an accused person considered innocent until proven guilty, and yet an acquittal doesn't necessarily result in a declaration of innocence?

What is essentially an exercise in semantics has become a hot debate among lawyers, legal experts and academics, particularly after the wrongful-conviction cases of Steven Truscott and William Mullins-Johnson ended in acquittals but not in legal findings of innocence by the court.

And with a public inquiry set to begin next month into the work of disgraced forensic pathologist Dr. Charles Smith, whose findings played a role in some 19 other cases, the subject isn't likely to go away anytime soon.

"There is simply no jurisdiction in court to essentially offer a verdict of innocence, no matter how deserved it may be," Crown prosecutor Michal Fairburn told an Ontario Court of Appeal panel Monday before Mullins-Johnson was acquitted of the 1993 rape and murder of his four-year-old niece, Valin.

On Friday, the Appeal Court agreed.

In its written reasons for Monday's acquittal, the justices wrote "just as the criminal trial is not a vehicle for declarations of factual innocence, so an Appeal Court ... has no jurisdiction to make a formal legal declaration of factual innocence."

Experts now say the girl died of unknown natural causes, not of strangulation during a sexual assault, as Smith and other pathologists indicated at the time.

All sides essentially agree that no crime ever took place and that Mullins-Johnson, 37, of Sault Ste. Marie, Ont., should never have been charged - let alone convicted and jailed for 12 years.

"That Mullins-Johnson was arrested, convicted of first-degree murder and spent 12 years in prison because of flawed pathology evidence is a terrible miscarriage of justice," the court's decision reads.

Despite earnest apologies from both the court and the attorney general, Monday's acquittal differed little from a not-guilty verdict, which is what happens when the Crown fails to prove its case beyond a "reasonable doubt."

Lawyers for Truscott, convicted in 1959 for the rape and murder of 12-year-old classmate Lynne Harper, urged the Appeal Court to not only acquit their client, but declare him innocent as well.

"An acquittal and a belief in innocence go hand in hand, in our submission," lawyer James Lockyer told the panel in February.

"As you move towards one, it is our submission that you inevitably move toward the other."

In the case of Truscott, who was acquitted in August, the absence of any iron-clad evidence, such as DNA, made it impossible to find him "factually innocent," a five-judge panel said in a 300-page decision.

On Monday, Fairburn urged the court to tread lightly in the case of Mullins-Johnson - any "official" statement proclaiming "factual innocence" would be "tantamount to a verdict of innocence," she said.

That would ultimately "dilute the meaning of the not-guilty verdict" and create a "three-tier verdict system," Fairburn argued.

She said Canada's Criminal Code doesn't give judges the same leeway as the system in Scotland, which offers three verdicts: guilty, not guilty and not proven.

"If there is to be such a significant change to our available verdicts, it should come through legislation from Parliament," the Crown concluded in its factum.

California also allows those who have been wrongly convicted to seek a "declaration of factual innocence" in a separate proceeding once they've been acquitted, the factum noted.

The Appeal Court's written decision for Mullins-Johnson acknowledged "important policy reasons for not, in effect, recognizing a third verdict, other than guilty or not guilty, of factually innocent."

"To recognize a third verdict in the criminal trial process would, in effect, create two classes of people: those found to be factually innocent and those who benefited from the presumption of innocence and the high standard of proof beyond a reasonable doubt," the court wrote.

York University law professor Alan Young said he supports the idea of multiple verdicts, given the myriad reasons for which a person might be acquitted, such as a lack of evidence, a technical error or true innocence.

But it's unlikely to happen, said Young, who also noted that ambiguous verdicts often put less pressure on a government to provide financial compensation in cases of wrongful conviction.

"This is just a very strange, asymmetrical component of the justice system," Young said.

"We don't seem to have any reluctance to declare people guilty beyond a reasonable doubt and we do it every day, but never ask a jury or a court to declare someone innocent beyond a reasonable doubt." The courts should have the limited power to declare innocence under the unique circumstances of a ministerial review of a suspected wrongful conviction and miscarriage of justice, he added.

In the absence of declaring someone innocent, often the best affirmation comes in the form of financial compensation and being cleared in the court of public opinion by way of media coverage, said Andy Rady of the Canadian Council of Criminal Defence Lawyers.

"DNA is certainly the great boon for showing innocence in the truest sense of the word, but you don't always have that DNA evidence," he said, noting even then there will be people who disagree.

"That's the stigma in our justice system even with being charged in many cases." University of Toronto law professor Peter Rosenthal suggested in the case of Mullins-Johnson, there's no need for a complete review of the verdict system.

"They can say there's not a scintilla of evidence pointing to this person's guilt except the completely bogus evidence of the pathologist," he said.

"They can say that without introducing a different verdict."