TORONTO -- The man convicted of killing eight-year-old Victoria Stafford seven years ago will ask Ontario's top court for a new trial Monday, trying to pin the blame on his accomplice.

Michael Rafferty was sentenced to life in prison in 2012 with no chance of parole for 25 years for kidnapping, sexual assault causing bodily harm and first-degree murder in the death of the Woodstock, Ont., girl.

His former girlfriend, Terri-Lynne McClintic, pleaded guilty in 2010 to first-degree murder, initially telling police Rafferty killed the girl, but testifying at his trial that she delivered the fatal blows.

Rafferty's lawyer, Paul Calarco, argues in documents filed with the Court of Appeal for Ontario that the judge made several errors, including failing to warn the jury against relying on the testimony of McClintic, "a person of unsavoury character, with a serious history of violence and lying."

The Crown's case was strongest on the kidnapping count, Calarco concedes, but since forensic evidence could not prove a sexual assault, that conviction was almost entirely dependent on McClintic's version of events, he argues.

"While the Crown had some evidence against Mr. Rafferty, the worst aspects of the case depend almost entirely on McClintic's evidence," Calarco writes.

"It was essential the trial judge give a clear, sharp warning against relying on her in the absence of substantial corroboration."

But the Crown argues there was in fact a significant amount of corroboration.

"Her testimony was supported by a compelling body of confirmatory evidence, including surveillance video footage; cellphone records; cell tower location data; forensic evidence; and analysis of the victim's blood and DNA from the appellant's car," Crown lawyers Howard Leibovich and Randy Schwartz write in documents filed with the court.

Defence at trial asked the judge not to give jurors such a warning, the Crown notes. The judge concluded that the jury could assess McClintic's demeanour in videotaped police statements, as well he took into account that the defence could cross-examine her, the Crown argues.

"The trial judge gave a fair and balanced charge and provided the jury with all the requisite tools to properly assess McClintic's testimony without highlighting the confirmatory evidence," the lawyers say.

"In the context of this trial it was impossible for the jury to not have been aware of McClintic's credibility problems. The trial judge properly exercised his discretion and committed no error."

Rafferty did not testify at trial, but argues in his appeal that he was "at most" an accessory after the fact to murder -- a concept the judge did not put to the jury.

His actions proven by evidence other than McClintic's testimony, such as cleaning the scene, destroying evidence and giving a false alibi, are "equally consistent with being an accessory," Calarco writes.

The trial judge told the jury that Rafferty's post-offence conduct can't help them in determining which offences he committed, and was right not to specify that they could also conclude he was an accessory.

"The appellant did not testify nor is there any logical reason to explain why the appellant, an innocent dupe according to the defence theory at trial, would assist McClintic in covering up this horrific crime," the Crown writes.

"It is not the function of the trial judge to invite the jury to speculate and provide instructions which were not requested and which find no support in the record."

McClintic told court a horrifying story of a drug-addled couple abducting a young girl at random for the man's sexual pleasure, then killing her with inconceivable brutality. She claimed Rafferty was directing her every step of the way, ordering her to snatch a young girl for him, making her buy a hammer and garbage bags then getting her to help him clean up at the murder scene.

The Crown at trial argued it didn't matter whether McClintic or Rafferty physically killed Tori -- he was guilty because they acted together.