Homicide investigators want to trace the Janzen family's steps leading up to a triple homicide that rocked a Fraser Valley community in B.C. last week.

A post on Randy Janzen's Facebook page appeared to be a confession that he killed his 19-year-old daughter Emily because she was suffering from migraines and depression.

He's also believed to have killed his wife, Laurel, and sister, Shelley.

"At this point, our priority is to speak with anybody who had been in contact with the Janzen family in a three-week period leading up to the incident on May 7," says Sgt. Stephanie Ashton.

'He was somebody who was thoughtful, pleasant, certainly committed to doing that which was right in his mind, so all of this is really a contradiction to the man I knew' - Pastor Phil Wheaton

Police believe the victims of the triple homicide under investigation are members of the Janzen family, although the BC Coroners Service has not yet confirmed their identities.

"Three badly burnt bodies have been located and this is consistent with what was posted on Facebook by Randy Janzen," Ashton added.

Police believe one of those bodies found at the Rosedale Popkum residence that burned in the fire is that of Randy Janzen, who died after a standoff with police.

A fourth body, believed to be Janzen's sister, was found in Langley.

Apparent confession posted to Facebook

​The Facebook post from the man identified as Janzen contains an apparent confession to the killings.

'Three badly burnt bodies have been located and this is consistent with what was posted on Facebook by Randy Janzen,' police say. (Randy Janzen/Facebook)

"I took a gun and shot her in the head and now she is migraine-free and floating in the clouds on a sunny afternoon, her long beautiful brown hair flowing in the breeze, a true angel," the post says.

"Now my family is pain free and in heaven," it concludes. "I have great remorse for my actions and feel like the dirt that I am."

The post says he shot his wife "because a mother should never have to hear the news her baby has died" and, "a couple of days later," killed his sister, "because I did not want her to have to live with this shame I have caused all alone."

The post is signed "Love Daddio."

The CBC cannot confirm that Janzen actually wrote the post.

Memorial planned for Janzen family

Those who knew the Janzen family are struggling to find ways to cope with their deaths.

Rocky Riobo is dealing with the loss of her best friend Emily Janzen, who she describes as a talented musician.

"She only got 19 years but she worked her way into a lot of people's hearts. It's kinda corny but she did."

Riobo said Emily's home life was stressful and she struggled with her difficult migraines.

"But her dad was there and took her to appointments and I know it killed him to see her in that kind of pain," Riobo says. "He was a really nice guy."

Pastor Phil Wheaton also described Janzen as a caring man.

"He was somebody who was thoughtful, pleasant, certainly committed to doing that which was right in his mind, so all of this is really a contradiction to the man I knew."

The Bethel Mennonite Church in Langley — where the family had ties — is planning a memorial. Those who sang with Emily Janzen are raising funds online for a musical education bursary in her name.