The mother of murder victim Josh Warneke says seeing innocent Aboriginal man Gene Gibson walk free after almost five years behind bars is "one of the most profound moments" of her life, as police launch a fresh probe into her son's death.
Mr Gibson, who is from the remote desert community of Kiwirrkurra and is cognitively impaired, had been serving seven-and-a-half years' jail after pleading guilty to manslaughter for bashing the 21-year-old as he walked home from a night out in Broome in 2010.
After the WA Court of Appeal unanimously ordered an acquittal on Wednesday, with reasons to be published later, Mr Warneke's mother Ingrid Bishop wished the 25-year-old the best.
"It's been a long haul for everyone involved and to see him walk free is one of the most profound moments of my life.
"I wish Gene, Alamay and his family all the very best as they start the next stage of their lives, and wish them strength and courage as they begin to heal and rebuild."
Ms Bishop said the appeal highlighted the "numerous deficiencies and incompetence" in how the Aboriginal Legal Service managed his case.
"The very agency tasked with protecting and supporting Gene failed, and failed dismally, and has taken the process of justice back 50 years for Aboriginal Australians."
Mr Gibson's lawyer Michael Lundberg said it was hoped Ms Bishop would one day obtain justice.
The conviction was appealed on the basis Mr Gibson suffered a miscarriage of justice because he did not have the cognitive ability or language skills to understand what was happening during the legal process.
He told the court last week through an interpreter that he gave a false confession because his counsel Dominic Brunello said he'd get a longer jail term if he pleaded not guilty, which the lawyer denied saying.
Mr Lundberg noted reviews by the Corruption and Crime Commission and WA Police's internal affairs unit provided the catalyst for the appeal.
But he said there were no winners because Mr Warneke had lost his life, while Mr Gibson had been in custody since his arrest at the age of 21, and away from his country and family for a long time.
"Josh and Gene have never met but their lives are now intertwined," he told reporters.
Mr Lundberg said it was too early to consider compensation.
WA Police Commissioner Karl O'Callaghan revealed the special crime squad was launching a new investigation into Mr Warneke's murder, and Ms Bishop said she was looking forward to it.
Mr O'Callaghan "deeply regretted" police failures that contributed to the unusual case, which was a "multi-faceted failure in the justice system", and said he would meet with Mr Gibson.
He said three of the 11 officers who faced an internal review recently formally advised they did not accept the 2015 findings and made no expression of contrition, which meant they would now face a disciplinary hearing.
WA Police Union president George Tilbury said the officers acted in good faith and without malice.
"Every single one are remorseful, regret the part they played and have accepted their role in this investigation," he said.
"However, there are key points of difference surrounding facts."