EVEN on the day he was arrested for murder, cocky ex-cop Louis Mahony was so confident he'd get off, he told officers they would soon be shouting him drinks to apologise.
For six years Mahony thought he had fooled the world after ruthlessly disposing of an inconvenient wife.
He'd staged the scene to make it appear that Lainie Coldwell, his defacto wife of 18 years, had fallen from a ladder at their Charleville home on August 23, 2009.
It convinced the country cops, who didn't realise they were staring at the murder weapon - a bloody antique iron lying among rocks where Lainie supposedly fell and struck her head.
Mahony thought his dreams were in reach - he had Lainie's multimillion-dollar life insurance policies to cash in.
He was also free to pursue the foreign women on 457 visas at the local abattoir, where he worked after leaving his former career as a Northern Territory police officer.
The flies in the ointment were detectives from the state's homicide squad, brought in to reinvestigate the case years after Lainie's supposed freak accident.
"He said to me, 'Renee, one day when this is all over, you are going to buy me a beer and apologise for what you've done to me'," Detective Renee Hoile recalls of the day she arrested Mahony in December 2015.
Mahony's prediction was proved spectacularly wrong last week, when he was convicted of killing Lainie, the mother of his young daughter.
With the 43-year-old sentenced to life imprisonment, the inside story of his downfall can now be told by the detectives who brought him to justice.
They revealed how a calculating and "narcissistic" Mahony initially researched car crashes and poisons before deciding to stage a fatal fall. He spent the day of his wife's funeral planning a romantic getaway with a lover.
It's hard to escape comparisons with Queensland's other egotistical wife-killer, Gerard Baden-Clay, who murdered wife Allison in 2012 and thought he could escape justice.
In both cases, the accused was involved with other women and stood to benefit from large insurance payouts. And in both, the women standing in the way of a life of ease and fortune ended up dead.
Interestingly, insurers were the first to raise the alarm about Mahony. About two weeks after Lainie died, they contacted Charleville police to report they had more than a passing interest in the case.
Two life insurance policies worth a whopping $2.25 million had been taken out in Lainie's name in the two months before her death. Suspicions were so grave, the company refused to pay out the policies.
In 2009, it had been Mahony who made the triple-0 call, saying he found Lainie unconscious in a puddle of blood at the base of a large gum tree. She must have fallen taking down party lights in the tree, he said.
Lainie, 36, was flown to the Royal Brisbane Hospital, with Mahony by her side. Her family made the agonising decision to turn off her life support system and donate her organs.
At the scene, a rusted and bloodied antique iron lying among rocks at the base of the tree was photographed but not collected. It has not been found since. It is now believed Mahony used the iron to deliver a fatal blow to the back of his wife's head.
In a tragic series of failings, a lone detective in Charleville made little headway before moving away, leaving the case to stagnate.
Local sergeant Gerard Thornton always had his suspicions and tried to pursue the investigation between other duties before calling in Brisbane-based homicide detectives in early 2013.
The case had an unusual complication. Because Lainie's organs were donated, an autopsy had not been conducted. So, Detective Hoile and colleague Karen Murray set about contacting the medical specialists brought in from hospitals around the southeast to work on the organ donation process.
They confirmed that Lainie's only significant injury was a single blow to the back of her head.
Lainie had supposedly fallen at least five metres from a ladder propped on the tray of Mahony's ute.
"There were no ribs broken, no other organs injured," said Detective Inspector Damien Hansen, who manages the homicide squad.
Photographs from the scene showed blood had inexplicably seeped onto the flat of the iron, which had been face down on rocks at the tree's base. Strands of Lainie's blonde hair were clearly visible amid blood on the underside.
As part of the original investigation, police had seized and held Mahony's laptop. When computer expert James Morris, a civilian from the Queensland Police electronic evidence examination unit, inspected the computer, he struck gold.
Before Lainie's death, Mahony had Googled terms including poisoning, car crashes, head injuries and forensic science. After her death, he was back online organising his love life.
"He's searching Gold Coast limousines and Dracula's Restaurant, and the Marriott Hotel on the Gold Coast. That's leading up to the funeral and on the day of her funeral," Detective Hoile says.
For a cop with an intimate understanding of police procedures, Mahony made plenty of mistakes.
In his triple-0 call, he twice said Lainie was face down.
"That's not possible if the injury is to the back of the head," Detective Hoile says.
Call records to insurers showed that before his wife's death, Mahony had asked whether they would pay out if someone died in a car crash but wasn't wearing a seatbelt. And compromising videos of Mahony and a Korean co-worker were found on his laptop.
Lainie was aware of Mahony's affairs and made it known that she was leaving him and taking their daughter, Dakota, then three.
Three years after he murdered his wife - while still a free man - Mahony remarried a wealthy divorcee. She continued to raise Dakota when Mahony was arrested in 2015, and she stood by him through his trial.
To this day, Detective Hoile is struck by Mahony's lack of remorse in robbing Dakota of a mother.
"There was never a time in my discussions with him where he ever displayed emotion when he was talking about her. If there was any emotion, it was about him," she said.