The man who was sentenced to life in prison for killing a Calgary couple and their grandson in 2014 is appealing his convictions and the Alberta Court of Appeal is hearing arguments from his lawyer on Thursday.

Douglas Garland, 59, was found guilty of killing five-year-old Nathan O'Brien and the boy's grandparents, Kathryn and Alvin Liknes, in 2014.

The three disappeared from the Liknes’ Parkhill home after an estate sale and were reported missing by Nathan’s mother when she went to pick him up from a sleepover and found no one at home.

Garland was charged with three counts of first-degree murder and was sentenced to consecutive life terms with no parole eligibility for 75 years.

In rendering his decision, Justice David Gates said the crime was carried out with 'meticulous planning and precision' and that ‘tools of his gruesome and barbaric acts’ were found at the Garland farm.

According to Garland’s lawyers there are multiple grounds for the appeal. They say one of the grounds for the appeal is that Justice Gates did not exclude evidence found on the farm at the jury trial.

On Thursday, alwyer Alias Sanders told the court that the defence took great issue with the search of the farm and Garland’s detention.

Sanders said the search of the Garland property was done to protect lives, as there were three people missing at the time, but that what was lacking was 'a reason these people were on the farm or any indication they would be there.’

The defence said evidence collected from the initial search of the farm ‘gave rise to the warrant.’

Sanders also said that when Garland was first detained and photographed that it wasn't consistent with his constitutional rights.

The defence said it had issues with how the trial judge spoke to the jury on several occasions regarding how difficult the evidence was and suggested that the comments were prejudicial.

The Crown said that clearly the appellant had a connection to the victims as Garland’s sister was married to Alvin Liknes’ son. Garland had also been involved in a business deal with Alvin and the Crown said that the relationship had soured and that the grudge had continued.

The Crown said that the trial judge provided three comments in a multi-week trial, acknowledged that the material the jury would see was difficult and said that ‘nothing reflected his personal view of the appellant’s guilt.’

The Crown said that the judge’s comments included talking to the jurors about taking a break and about self-care at the end of the trial and during deliberations, which was ‘keeping with his duty.’

The hearing wrapped up just after noon and the panel said it will reserve judgement but there was no indication when that would happen.

Nathan O’Brien’s parents attended Garland’s trial and were in court on Thursday.

According to the notice of appeal, the defence is seeking a new trial or a conviction on a lesser sentence.