New South Wales police have offered a $250,000 reward for information that leads to the arrest of Julian Ingram, the suspected triple murderer accused of fatally shooting his pregnant former partner, her boyfriend and her aunt in Lake Cargelligo in January.

Officials have searched for Ingram, also known as Julian Pierpoint, since 22 January. The 37-year-old was last seen driving a Ford Ranger ute with council signage.

Ingram is accused of murdering Sophie Quinn, 25, and her unborn child; John Harris, 32; and Nerida Quinn, 50. A 19-year-old man was also allegedly seriously injured in the attack.

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Police said multiple teams, including search and rescue and tactical operations, had been searching the Lake Cargelligo area for nearly two months. The reward reflected the need for broader community support to help find Ingram, officials said.

The assistant commissioner Andrew Holland said on Tuesday: “To anyone aware of his whereabouts – let this reward be the prompt for you to break your silence and assist police.”

Holland told reporters in Dubbo that “we believe he is being supported by someone in the community”.

“Seven weeks in the arid country … he would have to have support. He hasn’t accessed any of his mobile phones and banking … or anything of that kind. We believe he is alive and is getting support.”

Holland said the funerals for Sophie and Nerida Quinn would be held this week. “There will be a large police presence at those funerals to make sure the community is safe and to make sure that Ingram does not return,” the assistant commissioner said.

Paul Pisanos, the NSW police deputy commissioner for regional field operations, said “we’re calling on members of the public to come forward with what they know, to help police locate this man and bring closure to Lake Cargelligo and surrounding communities”.

The state’s police minister, Yasmin Catley, said in a statement: “This was a shocking and brutal act of violence that has left families grieving and a community deeply shaken.”

“The NSW police force will not stop working to locate Julian Ingram, and this $250,000 reward is about encouraging anyone with information to come forward,” Catley said.

“If you know anything about his whereabouts, now is the time to speak up. Even the smallest piece of information could help police find him and ensure those responsible for this horrific crime face justice.”

Police have faced scrutiny over a decision to grant Ingram bail for allegedly assaulting Sophie Quinn two months before the alleged murders.

Officials maintain that a risk assessment at the time found he did not pose an unacceptable risk and he had complied with court orders in the past.

Ingram was convicted of grabbing a family member by the throat after she made a comment about his children, four years before he allegedly murdered the three people.

He separately told a former partner he had a “gun and a hole” for a man he assumed to be her new partner and made threats towards her, their child and her mother a decade ago, according to court documents.