Lawyers for convicted murderer Travis Vader are asking the court to throw out two findings of second-degree murder and declare a mistrial.

And if a new trial is granted, Vader wants a judge other than Court of Queen's Bench Justice Denny Thomas to hear the case.

In a notice of application filed Thursday, Vader's lawyer, Brian Beresh, said the Sept. 15 judgment by Thomas is a "nullity" — legally void — because the judge improperly used Section 230 of the Criminal Code to find Vader, 44, guilty of two counts of second-degree murder in the deaths of St. Albert, Alta., seniors Lyle and Marie McCann.

As legal experts pointed out within minutes of Thomas issuing his ruling, the Supreme Court of Canada has previously found Section 230 unconstitutional. That means it is no longer in effect as a law, although the Canadian government has yet to remove it from the Criminal Code.

Since Thomas has already found Vader guilty of second-degree murder, Beresh argues he should not be involved in any new trial.

"A re-hearing and re-determination of the applicant's charges, or any of the factual elements thereof, by the same decision-maker [Thomas] would constitute an abuse of process, would tarnish the integrity of the court, and would bring the administration of justice into disrepute," the application states.

Thomas will preside over the mistrial application, which Beresh has asked to be heard on Oct. 3.

In the application, Beresh argues the court can't impose a sentence on Vader for the second-degree murder convictions because the offence for which he was convicted doesn't exist in law.

Vader had originally been charged with two counts of first-degree murder. Thomas found Vader not guilty on those charges. Beresh now argues that judgment is final and can't be altered.

"However, since a sentence has not yet been imposed, this court is empowered to reopen and vacate the two guilty verdicts [for second-degree murder] pronounced on Sept. 15, 2016, on the basis of 'exceptional circumstances,' such circumstances being present in this case," the notice of application states.

Unconstitutional law applied

Section 230 allowed for a murder verdict if a wrongful death occurred during the commission of another crime, such as robbery. But the Supreme Court found it to be unconstitutional in 1990.

The court ruled Section 230 violates Section 7 of the Canadian Charter of Rights and Freedoms, which protects the right to liberty. It ruled an accused can't be found guilty of murder and be subjected to the harsh consequences of that conviction if there is no proof an accused was aware a victim would die.

The revised definition of murder states the killings must be intended to be murder, which the Crown was unable to prove in the Vader case, legal experts say.

The mistrial application argues that if the court agrees to throw out the second-degree murder judgments, Thomas should not be allowed to re-hear the case. It says there would be a reasonable apprehension of bias since he had already convicted Vader "without completing the necessary analysis of the evidence."

The court could find Vader guilty of manslaughter, but Beresh argues that it would first have to determine his client wasn't guilty of the greater offences of either first-degree or second-degree murder.

Trial plagued by delays

If a mistrial is found, the already years-long legal process would start over again and could possibly place the entire prosecution in jeopardy.

Beresh had previously sought to have the charges against Vader dropped because of what he argued was an unreasonable delay by the Crown in prosecuting the case. The Crown stayed the charges against Vader in March 2014 but refused to say why at the time.

The charges were reactivated in December 2014. Then, in late November 2015, Vader attempted to have the charges stayed due to what he claimed was abuse of process and because of the ongoing delay in the prosecution.

At that hearing, Edmonton's chief Crown prosecutor testified she had lost all confidence in the RCMP's ability to turn over evidence.

Thomas, however, rejected the request for a stay of proceedings but said that, on the issue of the delay, it was "a very close call."

Judge made 'irreversible' error, Vader lawyer says

Beresh has previously said the error by Thomas in applying Section 230 — which has not been admitted — was "irreversible and the only answer is a new trial or a stay of proceedings pursuant to Section 11(b) of the charter." Section 11(b) of the Canadian Charter of Rights and Freedoms states that any person charged with a crime has a right to be tried within a reasonable time.

The McCanns disappeared in early July 2010 after starting a summer road trip to British Columbia. Their motorhome was found in flames at the Minnow Lake campground near Edson, Alta., two days after the couple left on their trip. Their SUV was found several days after that. The McCanns' bodies have never been found.

Thomas ruled the evidence showed they were the victims of a robbery by Vader, who was broke, drug addicted and desperate at the time.

Thomas placed significant weight on DNA evidence that tied Vader to the McCanns' SUV. Several witnesses also testified that Vader was driving the SUV. The judge also found Vader had used the McCanns' cellphone near the time of their disappearance.

Vader remains in custody.