Dezi Freeman, 56, was still at large on Friday following the fatal confrontation on Tuesday at a property in Porepunkah, about 300km northeast of Melbourne.
Victoria Police arrested a 42-year-old woman and a 15-year-old boy on Thursday night following an operation at an address in Chandler Court near the town centre.
The pair has since been released pending further inquiries.
On Friday, the street was quiet and the curtains on the property, where two cars were parked out front, were drawn.
The arrests are related to the police search for Freeman, who is married with three children.
Speaking near the Chandler Court address on Friday, Marlie Thomas said Freeman had become more withdrawn in the days before the fatal shootings.
She attends the local Our Lady of Snows Catholic church alongside Freeman and his wife.
"We knew he was withdrawing a little bit," she told AAP.
"We said, 'we've got to keep a closer eye on him'."
She urged Freeman to "please come in, hand yourself in".
A Special Operations Group helicopter circled the property around 8.30am on Friday, and a convoy of police cars including an armoured Bearcat vehicle was seen soon after.
Officers will on Friday scour mines, caves and dugouts for Freeman, who is heavily armed, as tough weather conditions continue to impact the search.
Freeman - also known as Desmond Filby - fled into bushland after he allegedly killed Detective Leading Senior Constable Neal Thompson, 59, and Senior Constable Vadim De Waart, 35, at a Porepunkah property on Tuesday.
Prime Minister Anthony Albanese on Friday paid tribute to the dead officers, calling them heroes.
"Detective Thompson and Senior Constable De Waart are heroes, and we also give our thoughts to those who have been injured during this incident," he told Nine's Today show.
Another wounded officer, 56, who was among a group of 10 attempting to serve a search warrant relating to alleged child sex offending, remains in hospital after being shot in the lower body.
"This guy (Freeman) is clearly dangerous. He's on the run and we want him caught," Mr Albanese said.
Weather conditions on the ground are expected to deteriorate on Friday, bringing wintry conditions including snowfall to 600m above sea level.
Every available asset and police capability was being deployed on the ground to apprehend Freeman, Deputy Commissioner Regional Operations Russell Barrett said.
"That's our purpose, and we will not rest until it occurs," he said on Thursday.
Superintendent Brett Kahan said the terrain was difficult and dangerous.
"It's not something that we, even with our specialist resources, can move through quickly," he said.
Anyone assisting Freeman has been urged to reconsider or risk serious punishment, while the accused gunman himself was urged to surrender.
"Ring triple-zero, and we will support a surrender plan. That option is absolutely open to him," Supt Kahan said.
Det Snr Const Thompson was cut down in his "last week or so" of work before retirement, and Snr Const Vadim De Waart had a "great career in front of him", Mr Barrett said.
Freeman, who has bush survival experience, was last seen wearing dark green tracksuit pants, a dark green rain jacket, brown Blundstone boots and reading glasses, police said.
He is believed to be a sovereign citizen, an ideology that rejects government authority and whose followers believe the rule of law doesn't apply to them, and who disassociate from society.
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