Canada's justice minister has promised to review a section of the Criminal Code that last fall forced an Edmonton judge to vacate Travis Vader's second-degree murder conviction in the killings of two Alberta seniors.

Vader was later found guilty of two counts of manslaughter. He was sentenced Wednesday to life in prison for killing Lyle and Marie McCann, a St. Albert couple last seen alive in 2010.

But the use of a so-called "zombie law" in Vader's original conviction nearly derailed the legal proceedings after the defence filed an appeal. The law had been declared unconstitutional but remained on the books and was cited by the judge in his ruling.

In a statement released just hours after Wednesday sentence was handed down, Justice Minister Jody Wilson-Raybould once again pledged that her department is reviewing the Criminal Code.

"My primary goal is to ensure our legislation meets the highest standards of equity, fairness and respect for the rule of law, as well as the Constitution of Canada," Wilson-Raybould said in a statement issued Wednesday night.

The minister said in November she had launched a broad review to update the Criminal Code.

‚Äč"As a concrete step towards achieving this goal, I have already instructed my officials in the Department of Justice to conduct a review of Criminal Code provisions found to be unconstitutional, with a view to updating the Criminal Code to reflect these decisions," Wilson-Raybould said Wednesday.

"Cases like this highlight the crucial need for such a review."

After a lengthy trial, Vader's defence lawyers were able to challenge his original second-degree murder conviction because the presiding judge relied on a section of the Criminal Code that had been deemed unconstitutional.

Section 230 allows for a murder verdict if a wrongful death occurs during the commission of another crime, such as robbery. But that section was found unconstitutional in 1990 by the Supreme Court of Canada.

Bret McCann

Bret McCann has been calling on the federal government to repeal parts of the Criminal Code which have been deemed unconstitutional. (CBC)

The section, however, was never repealed from Canada's Criminal Code.

Vader's charge was reduced to manslaughter as a result of the legal error.

Bret McCann, the McCanns' eldest son, wants these so-called "zombie laws" abolished so they can't come back in future trials.

"This caused our family a tremendous amount of pain," McCann said Thursday in an interview with CBC Radio's Edmonton AM. "I think it's just terrible to leave all these things in there. If this has happened to our family, it's going to happen to some other family in the future."

McCann had been campaigning for the review since Vader's contested conviction was handed down in September by Justice Denny Thomas.

He wrote to Wilson-Raybould last fall, urging her to clear out a backlog of unconstitutional sections in the Criminal Code.

"The pain endured by my family because of this so-called 'zombie law' was enormous," McCann wrote in his letter.

"In my opinion, after having suffered the consequence of such laziness, I think that it is very important that effort be expended by the government to maintain the correctness and completeness of the Criminal Code."

Though relieved by the prospect of a review, McCann said he had reservations about the scope of the federal review. The laws can be removed from the books swiftly with an omnibus bill, he said, so there is no need for bureaucratic delay.

"And I'd like to know when this is going to occur," he said. "These unconstitutional items, a small set of them could be easily removed. But if this is made part of a larger revamp of the Criminal Code, it could take much longer."