The officers were gunned down by James Roszko on his property near Mayerthorpe, Alta., in March 2005. Shawn Hennessey, 28, and his brother-in-law Dennis Cheeseman, 24, both of Barrhead, Alta., were charged last year with first-degree murder.
"They're jointly charged, so all the proceedings will be held...together," said Crown prosecutor David Labrenz.
Five weeks have been set aside for the hearing, although Labrenz indicated it may not take that long.
Police allege Hennessey and Cheeseman somehow helped Roszko before he shot the four Mounties, although it hasn't been revealed what the RCMP believe the two did.
Constables Leo Johnston, 32; Peter Schiemann, 25; Brock Myrol, 29; and Anthony Gordon, 28, were shot and killed while part of an investigation into stolen property and a marijuana grow-op. Roszko then killed himself.
Cheeseman was granted bail before the preliminary began Monday after he agreed in an Edmonton court to pay $10,000 in cash. Family members are putting up a $245,000 surety.
"That order doesn't take effect until Friday," said Labrenz. "In terms of what actually was said and happened at the bail hearing, it is the subject of a publication ban."
The judge ruled Cheeseman must abide by a curfew, get a job, stay in Alberta and have no contact with Hennessey.
Hennessey was granted bail last month on strict conditions and after providing a surety of at least $500,000.
