The Crown prosecutor in the Travis Vader case admits Queen's Bench Justice Denny Thomas made a legal error when he convicted Vader of second-degree murder in the deaths of Lyle and Marie McCann using a section of the Criminal Code that no longer exists.

Vader's defence lawyer, Brian Beresh, is seeking a mistrial, saying Thomas made a "colossal" error in law when he convicted Vader using Section 230 of the Criminal Code, which was struck down by the Supreme Court in 1990.

But Crown prosecutor Ashley Finlayson suggests there are other ways to correct the mistake.  

In a five-page brief filed with the court, Finlayson writes: "One potential remedy is to strike the two convictions for second-degree murder and to enter two convictions for the lesser and included offence of manslaughter."

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The McCanns, seniors from St. Albert, were last seen alive in July, 2010 when they left their home on a driving holiday to British Columbia. Their bodies have never been found.

In his brief, Finlayson notes that Thomas "found Mr. Vader killed the McCanns during commission of a robbery, that he intended to cause bodily harm to the McCanns to facilitate the robbery and that harm was inflicted … by Mr. Vader which resulted in their deaths."

The prosecutor suggests the judge could use those same findings to conduct an analysis using a different section of the Criminal Code and still reach the same finding of guilt on the second-degree murder charges.  

'The consequences of declaring a mistrial'

The Crown doesn't want Thomas to declare a mistrial.

In his brief, Finlayson asks Thomas to consider the consequences.

He points to an Ontario Court of Appeal decision that stated a mistrial should only be granted in the "clearest of cases," given the impact on the prosecution, accused, witnesses and the system as a whole.  

Crown prosecutor Ashley Finlayson. (CBC)

A mistrial can be declared if there is reason to believe the judge can no longer make an unbiased decision.

However, Finlayson writes, "The Crown submits … there is no reasonable suggestion that the court is biased."  

In conclusion, he writes that Thomas's decision "provides a firm foundation upon which the court can ensure that there is no prejudice to Mr. Vader."  

Judge agrees to hear oral arguments

Thomas originally told defence and Crown lawyers he would make a decision on the mistrial application Oct. 31 after considering their written submissions.

Justice Denny Thomas will hear oral arguments next Monday on a mistrial application launched by Travis Vader's lawyer.

He has now agreed to hear oral arguments on Monday.  It's unclear when he will deliver a decision on the mistrial application.

The CBC and other Edmonton media outlets have asked to livestream Thomas's decision.

Thomas will respond to the media's request Friday.