CALGARY -- The man accused of killing a five-year-old Calgary boy and the child's grandparents will have a preliminary hearing next May.

Douglas Garland, 54, made a brief court appearance in Calgary Wednesday.

Clad in a blue prison jumpsuit, Garland kept his head down and said nothing as the court set a two week hearing that is to begin May 19.

He faces two counts of first-degree murder in the deaths of Alvin and Kathy Liknes and one charge of second-degree murder in the death of Nathan O'Brien.

The trio vanished from the Liknes home in June.

Nathan had been at his grandparents' on a sleepover the night of June 29 after the couple held a sale at their Calgary home. They were selling their things as they prepared for a move to Edmonton and then on to Mexico.

When his mother went to pick Nathan up the next morning, no one was home. Police have said there was evidence of a violent incident in the house. They have not disclosed a motive.

Investigators searched several properties near the acreage in Airdrie, north of Calgary, where Garland lived. The search lasted for weeks but the bodies have not been found.

The preliminary inquiry will determine whether there's enough evidence to send the case to trial.

Crown prosecutor Shane Parker had the option of going directly to trial but said this will give him a chance for a test run of the evidence.

"I like the idea of a preliminary inquiry," Parker said outside court. "It gives us more time to make sure we're ready once the jury trial is slated to go."

Kim Ross, Garland's lawyer, said a preliminary hearing makes sense considering the vast amount of evidence.

"I think something of this complexity and nature requires a preliminary inquiry," he said.

Ross said he hasn't decided on whether to seek bail for his client.

He declined to respond to questions about why he has not requested a psychiatric assessment for Garland.

Allen Liknes, son of murder victim Alvin Liknes, was in court for the hearing as was a friend of Kathy Liknes. They both declined to speak with reporters afterward.

Parker said police will continue their investigation.

"We always want the investigations to continue on an ongoing basis all the way through," he said.

"We do have outstanding lab results that need to come back and there's other forensic type of evidence that they've got to finalize as well."

Parker said he is not willing to guess when a potential trial in the case could take place.