Julian Ingram, 37, has been at large since January 22 after an alleged domestic violence-related shooting spree at Lake Cargelligo in central-west NSW.
Ingram allegedly fatally shot three people, including his pregnant former partner Sophie Quinn and her aunt Nerida Quinn, hours after he reported for bail at a police station.
The victims are being laid to rest this week.
Surviving seven weeks in the arid outback terrain without assistance would be near impossible, police believe, fuelling suspicion someone has information that could lead to his arrest.
"Sixty thousand acres we've already covered ... there's probably another 600,000 acres we haven't," Assistant Commissioner Andrew Holland told reporters on Tuesday.
"At the scale of the area involved, he could be under a small area in the scrubland - there could be a vehicle involved."
In a bid to crack the case, police have issued a $250,000 reward for information to catch the council worker, last seen in a Ford Ranger ute with an emergency light bar on the roof.
Information from the public has slowed in recent times, after hundreds of tips had previously been investigated.
Senior police conceded bounty hunters had 250,000 reasons to track Ingram down.
"It could encourage a lot (but) what we're hoping it does encourage is a rock-solid lead that leads to his whereabouts," NSW Police Deputy Commissioner Paul Pisanos said.
Even the smallest piece of information could help police find Ingram, Police Minister Yasmin Catley said.Â
"Lives have been shattered as we now know. We want a community to feel safe again, and we believe you can help us," she said.
Ingram was on bail for domestic violence charges relating to alleged conduct against Sophie Quinn in late November 2025.
The case was paused on March 3 after he did not appear in court and warrants were issued for his arrest.
Asked about police confidence of finding Ingram, Mr Pisanos said it was a "difficult" question.
"We're committed to trying to find justice for the families, justice for these people that were brutally murdered," he said.
He previously warned the public that police would prosecute anyone helping the alleged murderer access food and water across the outback region.
If someone had previously assisted Ingram but came forward to provide information leading to his arrest, they would not receive blanket immunity, police confirmed.
Immunity would be assessed on a case-by-case basis.
An earlier tip-off led investigators to focus on the areas surrounding the remote outpost of Mount Hope, a former mining town about 90km northwest of Lake Cargelligo.
Two women said they came face-to-face with the alleged killer, saying he pointed a gun at them at a property.
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