A former prosecutor, Lloyd Rayney on Thursday was acquitted of murdering his lawyer wife, Corryn Rayney, and burying her upside down in a bush grave in Perth's King's Park in 2007. WA police said he was their only suspect. After his acquittal, Rayney had his day outside court. ''It's been five years since [his daughters] Sarah and Caitlyn have been without their mum - they haven't been treated well by many people - but apart from that … we still don't know what happened to Corryn,'' he said. ''Despite the best-funded investigation, despite unlimited, apparently, resources at the disposal of those people investigating, this is still unresolved and that is an extremely hard thing for my family to accept.''

Born in Yemen and of Irish-Indian descent, Rayney met Corryn Da Silva while working at the Australian Government Solicitor's office, where she was an articled clerk in the late 1980s. They married and had two children. A decade ago he was being tipped as the next WA Director of Public Prosecutions. Instead, he went to Bermuda in 2003 to work in the island's DPP office while she remained in Perth with the children.

Returning to Perth he went from high-profile prosecutor to high-profile defender, representing one of the bikies charged in a highly publicised Coffin Cheaters murder trial. He also built his profile in the commercial sector with the mining magnate Gina Rinehart among his client list.

But by August 2007, the couple's marriage was over. They no longer shared a bed. He had had an affair three years before. She had engaged in ''intimate touching'' with a ''school dad'' in her office, a house and a shed while her husband was in Bermuda. She was concerned about his gambling - he had lost $116,000 over a decade - and did not trust him.

The prosecution claimed the night she died Corryn Rayney had returned to the couple's home in the Perth suburb of Como to discuss splitting up. She had threatened to expose his infidelity and gambling.

She disappeared after her regular bootscooting dance class on August 7, 2007. Her abandoned Ford was found a week later in the distant suburb of Subiaco after the killer had run over a bollard and punched a hole in the transmission. Oil leaks from the car led police to her bushland grave. On August 20, police named Lloyd Rayney as the ''prime'' and ''only'' suspect. He was arrested and charged with wilful murder in December 2010. His trial began in July. Most of the evidence was circumstantial.

The trial was told a dinner party game card bearing Lloyd Rayney's name was found near the grave site, and forensic evidence tendered by the prosecution included two liquidambar seed pods found in Corryn Rayney's hair, soil and particles of paint and brick and damage to her boots to support the theory she had been dragged across the couple's suburban front yard.

The judge, Justice Brian Martin, spoke of ''extensive'' publicity that caused the case to become prejudicial to Rayney. It was the reason he was granted a judge-only trial. Curiously for a judge, Martin choked back tears as he delivered his verdict. ''The state advanced a case that using his experience as a prosecutor and barrister, the accused planned to commit the perfect crime. A moment's reflection reveals that this contention is not supported by the evidence,'' Martin said.

''The accused never displayed any physical aggression or extreme anger towards the deceased. At no time did the accused physically threaten the deceased or apply any physical force to her. The accused is a quiet and measured person who maintains his calm demeanour and appearance even in situations of stress …

''The deceased was not a quiet and reserved person. She possessed a friendly and outgoing personality, and was mentally strong to the point at times of being 'hard-nosed'.''

It was not the first time Rayney had attracted national attention. In May 1999, the late art critic Robert Hughes was driving on the wrong side of the road near Broome when his car collided with a vehicle carrying three drug runners. Horribly injured, Hughes spent the rest of his life suffering. Two of the men in the other car tried to blackmail him and WA laid dangerous driving charges against Hughes.

Rayney, then an ambitious rising star in the WA DPP's office prosecuted Hughes. The literary lion was acquitted but, outraged, he made scathing attacks on then DPP chief Robert Cock, QC, and dismissed Rayney as a ''curry muncher''. Both sued for defamation. The matter was settled privately. Hughes' sniffy verdict?: ''Western Australian justice is to 'justice' what Western Australian culture is to 'culture'.''

Indeed, the Rayney matter became a sort of WA justice system in the dock. Not only was Rayney of the fraternity, but Corryn Rayney had been a former WA Supreme Court registrar. The WA government brought in former Northern Territory chief justice Martin to preside and subcontracted the prosecution out to the NSW Department of Public Prosecutions. It cost WA taxpayers $3 million to prosecute Rayney.

The killer is still out there. The Rayneys did not have a butler.