A law in Western Australia allowing the state to indefinitely detain "high risk" offenders is constitutionally valid, the High Court has ruled.
Noongar man Peter Robert Garlett, 28, challenged WA's High Risk Serious Offenders legislation after being detained beyond his prison sentence for aggravated robbery.
Garlett had stolen a necklace and $20 in cash from two victims at their Perth home while pretending to be armed and threatening violence in the company of others.