A mother says her daughter’s killer should never be released into the community and wants major changes to Queensland’s mental health act.

A grieving mother is rallying for changes to Queensland’s mental health system to ensure her daughter’s killer never walks the streets again.

Sonia Anderson says her family shouldn’t have to relive the murder every six months at a mental health tribunal, which she fears may release the killer under the supervision of his parents.

Her daughter, Bianca Girvin, 22, was choked to death by her boyfriend Rhys Austin near the Mount Gravatt lookout in Brisbane’s south on March 30, 2010.

But Austin, now 26, will never face trial after the Mental Health Court found he was of unsound mind and was on “some sort of mission to kill”.

Attorney-General Jarrod Bleijie appealed against the decision but lost, meaning no further proceedings will be taken against Austin.

Flanked by more than 50 supporters in green shirts emblazoned with “Rhys Austin should never be released”, Ms Anderson said the system needed major change.

“We are not going to let the mental health system be a get-out-of-jail-free card anymore,” she told reporters outside Brisbane’s court complex.

“We need the community to know that every six months there is a mental health tribunal where people like Rhys Austin get reviewed with the ability to have limited community treatment, which means a degree of freedom.”

The Mental Health Court found while there was no question Austin killed Ms Girvin, based on a series of psychiatric reports, he was of unsound mind at the time.

Those reports said Austin murdered his girlfriend because his “computer God wanted him to do it”.

They also revealed Austin had previously thought about killing people, including an elderly couple who invited him into their caravan for a cup of tea.

Austin is being treated at a mental health facility for paranoid schizophrenia, with which he was first diagnosed in 2005.

Ms Anderson said the system had let her daughter down, and she is determined to have a say in looming changes to the state’s mental health laws.

Mental Health Commissioner Dr Lesley van Schoubroeck, who is preparing a submission on the review of the Mental Health Act, says the views of victim’s families will be taken into account.

“I absolutely believe we need to hear their voices,” she said.

It’s expected the types of orders the Mental Health Court can make will be expanded.

There is also a recommendation to review murder cases every seven years, rather than six months, but it’s unclear whether this would apply to Austin and other past cases.