Beaumont Lamarre-Condon, 28, is behind bars after being charged with murdering his former partner, ex-Ten reporter Jesse Baird, 26, and the man's new boyfriend Luke Davies, 29, in Sydney on February 19.
The senior constable is accused of using his police-issued firearm to murder the couple after using a key to access Mr Baird's Paddington home.
Police are searching an area in the Southern Tablelands of NSW for Jesse Baird and Luke Davies. (Mick Tsikas/AAP PHOTOS)
Investigators allege the crimes followed a months-long campaign of "predatory behaviour", culminating in the fatal shooting at the inner-city home.
It's believed Lamarre-Condon acted alone but divulged "partial admissions" to others before he handed himself in to police.
NSW Police officers on Sunday began to search dams at a property in Bungonia, near Goulburn almost 200km southeast of Sydney.
A search of rural land near to the property was expected to continue on Monday night and into Tuesday.
Deputy Commissioner David Hudson said the priority for police was to locate the bodies of Mr Baird and Mr Davies.
Police believe Luke Davies and his partner Jesse Baird have been shot dead. (HANDOUT/NSW POLICE)
"The accused has refused at this stage to assist us with our inquiries in relation to that, however, those inquiries will be ongoing," Mr Hudson told reporters on Monday.
He said the investigation had been difficult given the intense media and public interest in the case.
"We are investigating this to put a matter before the court ... and to also give some solace to the families and friends of these two deceased individuals, Jesse and Luke, and we're working very hard to do that at this stage," Mr Hudson said.
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