The former lead detective on the William Tyrrell investigation has broken his silence as a renewed search for the missing toddler's remains enters its third day.
Gary Jubelin led the investigation from five months after William's 2014 disappearance until he was removed in 2019.
Mr Jubelin, who has since left NSW Police, spoke to Ben Fordham on 2GB after Commissioner Mick Fuller said this week the Tyrrell investigation had been left in "a bit of a mess".
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Mr Jubelin claimed there was not "one ounce" of criticism during his handling of the investigation, and that he had filed regular reports that were passed up the command chain.
He said the criticism had motivated him to break his silence on the case.
"When there's criticism that came out, that came out from the Commissioner, that we were chasing people who proved to be not suspects - what really frustrates me about that is the lack of understanding of what a homicide investigation is," Mr Jubelin said.
"You've got to investigate everyone."
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Mr Jubelin said he supported police in the ongoing investigation.
"I'm not being critical of the police, I encourage the police," he said.
"If they've got a line of inquiry, I challenge them to follow it up to the nth degree."
But he said he had confidence in where the investigation stood when he had been "taken off it".
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https://omny.fm/shows/ben-fordham-full-show/shes-a-very-decent-human-being-former-detective-ga/embed?style=coverWilliam's foster mother was named a person of interest in the boy's disappearance this week.
She has not been arrested or charged over the disappearance.
Mr Jubelin said that at the time of his leaving the investigation, he was confident that no evidence had come to light which made him concerned either foster parent was involved in William's disappearance.
Mr Jubelin did not comment on the current state of the investigation, except to say that it was "a bit strange" to see it played out so "publicly".
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With police currently investigating the possibility that William may have fallen from the balcony of his foster grandmother's home in Kendall, Mr Jubelin said that possibility had been canvassed before.
"That's the most obvious place, when you look at the house, that a child could injure themselves," he said.
NSW Police Minister David Elliott, however, backed the current operation.
"I would expect that in any police investigation, they look at all scenarios, particularly when they put a fresh set of eyes on it seven years after it happened," he said.
Mr Jubelin also revealed when the case had initially been handed to him, the foster parents had already been ruled out as potential suspects.
"I might also say that - I think it was about 18 months into the investigation - that certain members of the Strike Force suggested there had were things that we needed to clarify with William's foster parents," he said.
"I wasn't overly concerned about it but they put it to me, so I thought for the sake of making sure we have covered every possibility - I basically ambushed the parents, and then I interrogated the parents, and I formally interviewed the parents, and then released the parents with a covert operation running."
That covert operation took the form of a listening device in the foster parents' car, Mr Jubelin said.
"And based on the answers to those questions and also the information that we gathered during the covert operation, they were again eliminated," he told Fordham.
He urged people to not be "armchair detectives", pointing to incorrect online accusations levelled at the family of Western Australia girl Cleo Smith after she went missing.
