The community of Abbotsford, B.C., is rallying to support the mother and sister of the little girl who was killed in Washington State over the weekend.

Five-year-old Clare Shelswell was found with her throat slit in a home near Lake Cushman, west of Seattle, on Sunday evening.

Her stepfather, Peter James Wilson, is being held in custody in connection with her death. According to court documents, he told investigating officers he suffers from bipolar disorder, and slashed the little girl after an argument with her mother.

At Mountain Park Community Church in Abbotsford, the congregation has been praying for Clare's mother Sarah Wilson, who attends services there.

"Last night there were groups just meeting throughout the city here, just praying for this family, so the support has been overwhelming," Pastor Cam Stuart told CTV News.

He said that it's a challenge for anyone to understand how someone could kill a child.

"Every time you try to make sense of it you hit a wall. For every question that you try to answer, there are another 10 questions that arise."

The church is in the process of setting up a trust fund for the family, as are neighbours Alison Taekema and Sean Brown, whose daughter attended kindergarten with Clare.

"I know what a financial hardship this is going to cost (Sarah Wilson). Just travelling back and forth, grieving, losing the time off work," Taekema said.

The couple can be reached through Brown's website.

Mood disorder expert Rennie Hoffman says it is almost impossible to predict violence from people suffering from bipolar illnesses.

"People with mental illness are usually more dangerous to themselves than they are to anybody else, but every once in while we get these headline-grabbing stories," he said.

A sombre ceremony in Clare's honour is scheduled for this Sunday in Abbotsford.

With a report from CTV British Columbia's Peter Grainger