The police focussed on David Lyttle as the potential killer, and ignored information pointing to a drug deal that went wrong involving Hall's criminal associates.
He eventually told an undercover police officer (Mr Big) he committed the murder and claimed he cut the body in half.
Due to a series of failures by police to disclose relevant information to his defence team, Lyttle's trial was subject to numerous delays.
Influenced by his 'confession' to Mr Big, Lyttle was found guilty and sentenced to life in prison - with a non-parole period of 11 years.
In March 2021, the Court of Appeal quashed his conviction, stating that virtually nothing he told the police as part of their Mr Big operation carried any credibility.
Police learned that Hall was involved in a drug deal with the Mongrel Mob and other gangs at the time of his disappearance; and that he had previously been the victim of two home invasions at the property, in one of which, shots were fired.
However, he was repeatedly told he had to be honest with them, confess to any crimes he had previously committed, and eventually, he could join the organisation and receive a 'big pay day'.
Finally, Lyttle was introduced to a man known as 'Mr Scott', who was another undercover police officer posing as head of the criminal network.
He told 'Mr Scott' he shot Hall between the eyes with a .22 rifle, cut the body in half with a Stanley knife and a hacksaw, put the torso into one plastic bag and the legs into another, and then buried them at separate beaches.
[7] Lyttle's trial was frequently delayed because the police and the Crown refused to disclose vital evidence to his lawyers Christopher Stevenson and Elizabeth Hall.
The statement made to the police in March 2014 by an informant that Hall's murder was arranged by someone who had stolen drugs worth $200,000 from him was not given to Lyttle's lawyers until July 2017.
[7] In October 2017, Justice Simon France delayed Lyttle's trial once again, ordering the police to carry out an audit of what had been dislosed and what hadn't been.
As a result, hundreds more documents were released, including nearly all the notebooks of Detective Senior Sergeant Dave Kirby, one of the officers in charge of the investigation.
At the end of the first week, the officer in charge of disclosure, former detective sergeant John Gleeson, was on the stand when he realised large parts of his own notebooks had not been handed over.
Those notebooks included details of someone claiming to have been present when Brett Hall was killed, and that the murder was the result of a drug deal gone wrong.
His lawyers insisted he was induced into making a false confession by his reduced circumstances and the potential rewards that seemed to be on offer from Mr Big.
Research in the Journal of the American Academy of Psychiatry and the Law has found that false confessions induced by the police are a leading cause of wrongful convictions.
The Court agreed the Mr Big operation was "particularly manipulative" and that the so-called evidence from it should never have been heard by the jury, including Lyttle's confession.
But no trace of Hall's blood or DNA was found on Lyttle's clothes, or in his vehicle where he claimed he put the body for two days before he disposed of it.
[2] The Court of Appeal concluded: “The inherent implausibility of Mr Lyttle's assertions, and their lack of congruence with the objective evidence, lead us to the conclusion his admissions were, in all likelihood, made in order to convince Scott (Mr Big) to allow him into the organisation so that he could reap the rewards he expected to receive.”[7] Despite the Court of Appeal's clear-cut decision, crown prosecutor Michele Wilkinson-Smith said she intended to make Lyttle stand trial a third time.
At a two-day hearing in November 2021, defence lawyers, Christopher Stevenson and Elizabeth Hall, pointed out there was no longer anything which implicated Lyttle.
The Court of Appeal upheld this decision ruling that the female prosecutor was not to blame for the repeated failures of the police to disclose information.
It said the “litany of significant failures” by police in failing to disclose material to the defence was "egregious and an affront to the administration of justice".
Brett's mother, Lee Hall, thinks that all her murdered son wanted was to have his house finished and lead a quiet life.