The boy and his grandparents disappeared at the end of June from a house in southwest Calgary. Their bodies have not been found.
In July, Garland, 54, was charged with two counts of first-degree murder and one count of second-degree murder.
CBC News earlier learned there were soured business dealings between Garland and Alvin Liknes, including a patent dispute.
Garland, whose sister is in a common-law relationship with Alvin Liknes’s son, was arrested on July 14 following an extensive search of a property north of Calgary that is owned by Garland's parents.
During Garland’s last court appearance in August, Crown lawyers said there was still a substantial amount of evidence to be disclosed to defence counsel, prompting the judge to put over the case until Wednesday.