'Anomalies' in images could prompt further search for young Gus Lamont

When the lead detective in the investigation into the disappearance of four-year-old Gus Lamont spoke of the "unwavering commitment" of police, he couldn't stop a waver from briefly entering his voice before he regathered his composure.

"They are working their arses off, on this job, sometimes thanklessly," Superintendent Darren Fielke said of his fellow detectives on the case.

"They live and breathe this every day."

Superintendent Fielke, who is the officer in charge of SA Police's Major Crime Investigation Branch, made those comments at a media conference on Wednesday, on the eve of the first anniversary of Gus being reported missing from his outback home near Yunta.

Seasoned senior police officers are not in the habit of being publicly unrestrained in their feelings — the requirements of the job perhaps dictate against anything other than dispassionately professional demeanour.

But Superintendent Fielke's moment of emotion underlined the fierce determination of police.

"We're going to continue to thoroughly and meticulously investigate the disappearance of Gus until we get a resolution," he insisted.

Wednesday's media conference was the setting for two significant developments — a video appeal from Gus's grief-stricken parents, and the announcement of a reward of up to $1 million for information leading to a conviction over the boy's disappearance or to "the location of his remains".

"A reward is a legitimate strategy that we use in police investigations," Superintendent Fielke said.

"In the past 12 months we've paid out a significant amount of money for rewards, for cold case matters, that wouldn't have been resolved without a reward being offered, so we know they work.

"One million dollars is a life-changing amount of money for someone. Now is the time to come forward."

Strategically the right time

An incentive of that magnitude is not unprecedented in the history of South Australian policing.

Superintendent Fielke said there had been, in total, 17 missing children's cases that had prompted million-dollar rewards, and added that the latest one had been sought by police from the SA government "in the last few weeks".

Criminologist Xanthe Weston told the ABC she thought the timing of that move was right.

She said in the immediate aftermath of Gus's disappearance, police were inundated with information — "but clearly they need a push now".

"They've thought this through very carefully," Dr Weston said.

"It feels like it's been a long time, but actually, strategically, I don't think it would have worked earlier in the investigation.

"[Initially] the police were receiving a lot of information from the public that they certainly followed up."

Dr Weston cautioned that rewards were double-edged swords, and had the potential to elicit not just legitimate intelligence but false information.

"If somebody is involved in Gus's disappearance, it's likely they've talked to somebody. People generally don't keep these things totally secret to themselves," she said.

"What the police need is genuine information — what they don't need is people calling with theories and guesses."

'Anomalies' could prompt further search

The challenge presented by misinformation is one police are acutely aware of.

"We need people to come forward with information that will help drive this investigation forward," Superintendent Fielke said.

"Theories and conspiracies are not what we're looking for."

But police have multiple irons in the fire.

While the media conference was mostly focused on matters other than the strictly investigational, the chief detective's comments nevertheless offered a glimpse of a potential fresh line of enquiry.

Superintendent Fielke said detectives from Taskforce Horizon — the police unit established to investigate Gus's disappearance — had recently completed "a painstaking, methodical, forensically detailed manual" scouring of imagery gathered during aerial searches above Gus's home, Oak Park Station.

"As a result of that manual searching, we have identified some anomalies in the imagery that has been provided to us," he said.

"These anomalies are now being further reviewed and depending on how that review will plays out will determine whether we return to Oak Park Station and conduct further searching."

Asked to elaborate on what those anomalies are, Superintendent Fielke was reluctant, citing investigational reasons.

But he was adamant that, as the first anniversary of Gus's disappearance approaches, police are as "focused and determined" as ever.