Police in Perth have charged a 21-year-old man with the wilful murder of an eight-year-old girl at a shopping centre in the southern Perth suburb of Canning Vale.

Police say they arrested the man at a home in Canning Vale early this morning.

He has been charged with wilful murder, deprivation of liberty, and sexual penetration of a child, he will appear in court later today or early tomorrow.

The girl was murdered after being separated, for just 10 minutes, from her 14-year-old brother and her uncle while they all went to the toilet.

Her relatives went to the men’s room while she went alone to the women’s.

After she failed to return the pair searched both bathrooms, eventually finding her naked body in the disabled toilet.

The girl was a student at a local Catholic primary school.

A team of psychologists has been sent to the school to provide trauma counselling for staff and students.

Safety concerns

The West Australian Police Commissioner, Karl O’Callaghan, says parents may well be more cautious about the use of public toilets, but they should not panic.

"Look it’s a terrible thing and I think and we wouldn’t blame any parent from reconsidering looking after eight-year-old kids when they want to go to the toilet on their own," he said.

"It is a terrible crime but I don’t want everyone to panic about this."

Psychologists say the murder will have a significant effect on the behaviour of parents.

Crime Research Centre spokesman David Indermaur says the murder is likely to cause shock and panic in the community but parents should be realistic about the risk to their children.

"It is important not to create fear, especially in children," he said.

The executive director of the Property Council, Joe Lenzo, says the tragedy of the murder is magnified because it took place in a shopping centre where most people would feel safe.

He says moves are already under way to improve shopping centre security.

"This will only heighten the fact that we need to make sure that we make that environment as secure and as safe as possible for the customers," he said.

"That’s an ongoing effort by the shopping centre and the shopping centre council."