Dustin Duthie, a Calgary man accused of killing his girlfriend, mother and stepfather, sniffled and sighed as he was committed to stand trial on charges of first- and second-degree murder.

On Friday, following a two-week preliminary inquiry, provincial court Judge Sean Dunnigan order Duthie, 26, to be tried on one count of first-degree murder in the death of Alan Pennylegion, 51, and two counts second-degree murder in the deaths of Taylor Toller, 24, and Shawn Boshuck, 52.

A first-degree murder charge typically indicates the killing was planned.

Initially, Duthie faced three second-degree charges, but prosecutor Shane Parker asked for the upgraded charge in connection with the stepfather's killing.

Dustin Duthie is charged with three counts of murder in the deaths of his girlfriend, Taylor Toller, his mother, Shawn Boshuck, and his stepfather, Alan Pennylegion. (From left: Taylor Toller's Facebook page/Shawn Boshuck's Facebook page/Supplied)

A preliminary inquiry is held to determine if there is enough evidence for the accused to stand trial. A publication ban protects any of the evidence from being reported in order to protect the accused's right to a fair trial.

Parker and co-counsel Leah Staples called more than two dozen witnesses over the past two weeks.

Mental health concerns

Back in the summer of 2018, there were two separate killings, according to police.

Toller, 24, is believed to have been killed in her Applewood Park apartment as early as July 26.

Following a 911 call made by Duthie on July 31, police discovered the bodies of Boshuck and Pennylegion in their home in the northwest community of Hidden Valley.

That's when police attended Toller's apartment to check on her and found her body.

Following his arrest, Duthie was held first at the Rockyview General Hospital and then at the Southern Alberta Forensic Psychiatry Hospital before being moved to the Calgary Remand Centre.

They will be back in court Feb. 14 to set trial dates.