Breaking: Serial paedophile Dennis McKenna to be released within weeks

One of WA's worst serial paedophiles, Dennis McKenna, will be free within weeks after serving his sentence.

The Supreme Court has declared him a High Risk Serious Offender, placing strict supervision conditions on his release.

McKenna is currently behind bars for the second time, all relating to sexual abuse he inflicted while in charge of a school boarding hostel in Katanning in the 1970s and 80s.

Justice Marcus Solomon said McKenna's presence in the community carries the potential to re-traumatise victims, but that did not mean he could be locked up indefinitely.

"Re-traumatising of victims not a commission of offence, therefore the prospect of it happening — as appalling as it is — is not a power that allows continuing the detention of offender under the act," he said.

"However, it is a factor that can be taken into account during the crafting of the conditions."

McKenna will be subject to 41 conditions as part of the order, which will severely restrict his ability to move freely around.

The conditions include being banned from having contact with any of his 29 victims, children, attending parks with playgrounds, and having to report any relationships to corrective services officers.

He will also be banned from the town of Katanning.

In his decision, Justice Solomon said the court's job was to make an assessment of risk to the community, not punishment due to the offender.

"It should therefore be appreciated that this application has a necessarily narrow focus ... judges cannot permit glare of public interest, intensity of media chatter or their own indignation to distract them into commentary on politically or socially contentious matters," he said.

"When judges do so, they ... diminish confidence ... and undermine the administration of justice."

Kaye Anderson's two sons were abused by McKenna, and both died by suicide.

She was disappointed the state prosecutor did not consider requesting for McKenna to be locked up indefinitely.

She said life was "mental torment, day in, day out".

"I mean it just doesn't go away — and I don't think the justice system has realised how bad his offending was and he should never, ever be released," Ms Anderson said.

But she has vowed not to give up at the prospect of one day having McKenna behind bars again.

"Don't worry, I'm not giving up. I've still got life in me," she said.

McKenna abused students in the 1970s and 80s while he was the warden at St Andrew's Hostel, a boarding lodge in the town of Katanning, 290 kilometres south-east of Perth.

McKenna's brazen abuse of hostel students was revealed over the course of four separate court cases between 1991 and 2015.

He was jailed in 1991 but released after a year and 10 months on parole.

Police laid further charges in the late 2000s and he was jailed in 2011 for a 15-and-a-half year term.