The former police officer has pleaded not guilty to the February 2024 murders of Jesse Baird, 26, and Luke Davies, 29, saying they died of gunshot wounds sustained in two separate violent struggles in Mr Baird's inner-Sydney home.
Mr Baird - the accused's ex-partner - was meant to move out of the house the day after his death, frustrating his housemates when the belongings had not been moved.
"We planned for our new housemate to move in the following day so we were worried his belongings would still be there when she arrived," a housemate - known by the pseudonym Belinda Smith - told the murder trial on Thursday.
Hours after the two men were shot dead in the house, Ms Smith got home from work and noticed two surfboard bags covered by a tarpaulin in the rear courtyard.
Mr Baird had never spoken about surfing or stored surfboards at the house, Ms Smith said.
Having noticed a red liquid escaping from the bags, she took a photo and sent it to her other housemate, known as Sarah King.
"I thought it was rusted water from the outdoor furniture," Ms Smith said.
"You had no reason to suspect ... there was anything else in those surfboard bags?" prosecutor Brett Hatfield SC asked.
"No," Ms Smith replied.
The next day, the two bags and the spilled liquid were gone, but Mr Baird's belongings were still in the house.
"Sorry won't be able to make it tonight ... I'm leaving for Perth early tomorrow morning," Lamarre-Condon has previously been accused of messaging Ms Smith, while pretending to be Mr Baird.
Prosecutors allege the senior constable murdered the two men, returned in the afternoon to put their bodies in the surfboard bag and then went back late in the evening to remove the bags.
Lamarre-Condon shot Mr Davies deliberately through the bedroom door when the 29-year-old tried to call triple zero after Mr Baird was killed, Mr Hatfield said.
However, the officer claims he acted in self-defence and Mr Davies accidentally shot himself as he and Lamarre-Condon struggled outside the bedroom over the gun.
Defence barrister John Stratton SC questioned a senior crime scene officer about a bullet hole discovered in the bedroom door more than two years after Mr Baird and Mr Davies died.
"At no stage was a projectile or fired bullet found inside (the bedroom)," Mr Stratton said.
"That is correct," Senior Sergeant Bronwyn Lansley replied, confirming there was no mark indicating a bullet impact inside the room.
Mr Stratton queried whether the absence of the bullet, coupled with the hole found in the door, could suggest a fired bullet was lodged in the door and then removed.
"Testing indicates a bullet has exited through that side of the door," Sen Sgt Lansley said.
The forensic investigator agreed DNA found on the trigger of the officer's gun might have belonged to Mr Davies.
Forensic evidence about belongings found in a bowling club skip bin was earlier shown to the jury, including numerous photos of items allegedly stained with the blood of Mr Baird and Mr Davies.
Lamarre-Condon allegedly identified the skip bin as a place to dump the belongings when driving through Cronulla the day after killing the two men, according to prosecutors.
On a quilt cover, a footprint can be identified in dried blood which matched the tread of a pair of Adidas shoes found in Bungonia, where the two men's bodies were discovered, Sen Sgt Lansley said.
Also dumped were a set of four heavily stained AFL goal umpiring flags and league-branded shorts still in their packaging, the jury heard.
Mr Baird umpired in 62 AFL games including two finals during his four-year career in league football.
Personal items including a stuffed elephant toy, a silver watch and a wallet belonging to the two men were also dumped in the industrial bin by the officer, the jury heard.
The trial continues.
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