Beau Lamarre-Condon has pleaded not guilty to the February 2024 murders of Jesse Baird, his ex-partner, and the TV presenter's new boyfriend Luke Davies.
Evidence on Thursday focused on how investigators connected items and bodies found at a regional property with other discoveries in Sydney and how they linked to Lamarre-Condon.
Crime scene officer Greg Moon, who co-ordinated a forensic sweep of the Greek monastery at Bungonia where the men's bodies were found, explained how DNA and blood were analysed to match found items to the alleged murders.
Clothing appearing to match the disguise Lamarre-Condon wore during the killings - including a hi-vis jacket and motorcycle helmet - which was found dumped near the men's bodies, Mr Moon said.
Earlier in the trial, jurors were shown CCTV allegedly showing the heavily disguised Lamarre-Condon returning to the alleged murder scene laden with cleaning products and a tarpaulin.
The footage showed the senior constable buying a second surfboard bag in the hours after the killings.
The accused could not be ruled out as having DNA that matched a sample taken from the clothes near the men's bodies, the investigator said.
A pair of blood-stained black shoes also found had tread matching a bloody shoeprint found on bed linen in a skip bin in southern Sydney, Mr Moon said.
The accused allegedly dumped some of the men's belongings in a skip bin in Cronulla.
Close-up photographs of a gunshot wound to Mr Baird's right temple were also shown to the jury, but not to people in the public gallery.
Mr Moon walked the length of the jury box during his evidence to individually show each juror pinprick marks around the wound known as stippling, caused by particles coming out of a gun when it is fired.
The Crown alleges Lamarre-Condon, now 31, killed Mr Baird "execution-style" at close range, acting out of a jealous obsession that had grown violent after the pair's November 2023 split.
However, the former officer's barrister says Mr Baird, 26, and Mr Davies, 29, were killed in self-defence when they engaged the accused in two separate violent struggles.
Mr Moon said examining the stippling can give an indication to the distance between the gun and its target.
"The closer the firearm is to the target, the stippling will be quite condensed around the gunshot wound," Mr Moon said.
"The only area I saw stippling was around that gunshot wound on the right temple."
Many of the photos cannot be published publicly out of sensitivity to the men's families.
The bodies were discovered inside two surfboard or stand-up paddleboard bags, with the smaller bag containing the body zipped up inside a larger one, Mr Moon said.
Mr Moon said the bodies were discovered one on top of the other with rocks and small branches placed on top.
Fellow investigator Christine Abela said she immediately knew something was amiss when she arrived at the rural property more than a week after the two men were killed in the summer of 2024.
"There was a strong smell as soon as I got out of the car," she told a NSW Supreme Court jury on Wednesday.
Sen Const Abela detailed how investigators found concrete blocks, a gym weight and a cut padlock at Cella Farm, where Lamarre-Condon allegedly was unsuccessful in sinking the bodies in a dam.
Mr Moon said there were multiple indicators that the remains had been at the monastery for several days.
"A large number of maggots and other insects were present in the bags along with other decompositional fluids," he said.
His barrister says the actions to dispose of their bodies at Bungonia - 200km south of Sydney - were indicative of his panic about the unexpected deaths.
The 12-week trial will continue on Monday.
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