Cody Haevischer and Matthew Johnston were convicted last week of conspiracy and six counts of first-degree murder, seven years after the discovery of the bodies face down with bullets in their backs and heads.
On Monday, their lawyers asked the judge in the case to put off registering the convictions so they can call evidence into allegations of police misconduct involving the informer identified only as E5.
Before the year-long trial began, Crown lawyers and an independent third party appointed to assist the court held a closed-door hearing discussing how police dealt with the informer.
Neither the defence lawyers nor the accused ever heard the informer's evidence, and that person never testified at the trial.
"To outward appearances and perhaps only to outward appearances, I simply don't know we make the suggestion that the police handling of the informer, E5, would appear to have been lacking at best, and perhaps worse," Johnston's lawyer, Brock Martland, told a B.C. Supreme Court judge.
As part of the allegations of police misconduct, the defence lawyers will also argue there were problems with the conditions under which the accused were jailed, in particular after their arrests in 2009.
Several other legal submissions must be heard before the defence lawyers will get an answer on the abuse-of-process application. Justice Catherine Wedge will not hold a formal sentencing hearing where family members may give victim impact statements until those matters are decided.
Killed on Oct. 19, 2007 were Corey Lal and his brother Michael, associates Eddie Narong and Ryan Bartolomeo, and two bystanders, fireplace repairman Ed Schellenberg and Lal's neighbour Chris Mohan.
The sentence for Haevischer and Johnston carries a mandatory minimum of life in prison with no possibility of parole for 25 years. The defence has 30 days to file notice of appeal following the sentencing.
Another trial is slated for the alleged leader of the Red Scorpions gang, Jamie Bacon, who faces charges in relation to the deaths.
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Note to readers: This is a corrected story. A previous version incorrectly identified informer E5 as Person X.