The last of the young offenders locked up in an adult prison following a riot last January have been moved back to the repaired juvenile detention centre.
On January 20, Banksia Hill's teen detainees staged a riot, trashing 108 of 240 cells and leaving the prison almost uninhabitable.
The male detainees were moved to the nearby Hakea Prison for adults, fuelling anger among their parents and concerning Amnesty International, which backed an unsuccessful bid to challenge the legality of the transfer in the Supreme Court.
More than $3 million has been spent on repairs and improved security, and the first of the detainees are in the process of being returned to Banksia Hill, the Department of Corrective Services confirmed.
And today, Corrective Services Minister Joe Francis said that as of this week, no young offenders remained at Hakea.
"The transition had to be done properly, it had to be done carefully and it had to be done sustainably," Mr Francis told parliament.
"The juveniles are back at Banksia Hill and all is going well so far. It is a significant milestone in this regrettable history."In reports about the riot, Inspector of Custodial Services Neil Morgan concluded the riot was "entirely predictable", given the detainees were frustrated with almost constant lock-downs because of chronic understaffing, with many guards on worker's compensation leave.