LETHBRIDGE, Alta. - The jury in gruesome Alberta triple murder trial has a difficult road ahead even after they finish their deliberations, says a former juror who suffered post-traumatic stress disorder from his time in the jury box.

Deliberations are to begin Wednesday in the case of Derek Saretzky, 24, who is charged with first-degree murder in the September 2015 deaths of Terry Blanchette, his two-year-old daughter Hailey Dunbar-Blanchette and Hanne Meketech, who was killed five days before the father and daughter.

"It's a pretty awful one. I get about three-quarters through an article and I think, you know what, that's enough," said jurors' rights advocate Mark Farrant in an interview with The Canadian Press from Toronto.

Farrant spent five months at the 2014 trial of Farshad Badakhshan, who was ultimately convicted of murdering his 23-year-old girlfriend, Carina Petrache.

Farrant was later diagnosed with PTSD and has become an outspoken advocate for the need to provide counselling for jurors hearing horrific cases.

He said the jurors at the Saretzky trial have been bombarded with horrific images of blood and death. When some of the graphic evidence was shown during the trial, some jurors broke into tears and needed a break before they could continue.

That takes its toll every day, Farrant said.

"It's impossible not to take that home with you. That stuff lives with you. You are so wrapped up in that case, I would be surprised if you are thinking about anything else," said Farrant.

"Especially in a case as disturbing and heinous as the one involving Saretzky. I can't imagine that they wouldn't be wrapped up in that."

The jury has heard a video confessions where the accused told police he bludgeoned and stabbed both Blanchette and Meketech. He also admitted to choking the little girl and then dismembering, cannibalizing and burning her body.

Although no real motive emerged during the trial, Saretzky told police he was being told by the devil to do bad things.

He has pleaded not guilty to three charges of first-degree murder and to a count of causing an indignity to the girl's body.

Court has heard Saretzky knew all three victims, as well as Hailey's mother, Cheyenne Dunbar, who he claimed to have dated. Dunbar testified that they were only friends.

Farrant said a jury has to separate emotion from the simple facts of the case.

"You might feel through the case a number of emotions - revulsion, you might feel hostility toward that person and anger - but really you can't let that cloud what you do at the end of the day."

Fourteen jurors have heard all the evidence, but in the end only 12 will determine guilt. Farrant feels sympathy for the two alternates who are dismissed.

"I've heard that from a number of jurors saying that in some ways is barbaric. The feeling that I sat through months and months of this and am told through a lottery that I'm not the one to see this through," Farrant said.

Farrant said jurors shouldn't wait to seek counselling once the case is over.