The jury in his NSW Supreme Court trial was shown hundreds of forensic images from various crime scenes involved in the 31-year-old police officer's alleged double murder.
The former senior constable pleaded not guilty to the murder of Jesse Baird, 26, and Luke Davies, 29, in the former's Sydney terrace in February 2024.
Images released by the court show how forensic investigators found dozens of blood stains in and under the Paddington house in the days after the killings.
Crime scene officer Senior Sergeant Bronwyn Lansley explained to the 15-member jury how luminol, a chemical that highlights areas of possible blood staining, was used throughout the house.
The prosecution alleged Lamarre-Condon killed Mr Baird "execution-style" in the kitchen, before shooting Mr Davies through the bedroom door when he attempted to call triple-zero.
The officer then spent hours in the coming days attempting to clean the scene before handing himself in, prosecutor Brett Hatfield SC said.
Lamarre-Condon says he killed the men in self-defence and they died from gunshot wounds during two separate violent struggles.
While some evidence of blood was found on the floors and walls of the house, it was when investigators searched under the floorboards they made more notable discoveries.
A tarpaulin with a stain from pooled blood was found underneath the bedroom, Sen Sgt Lansley said.
There was also extensive staining on the underside of the floorboards and the joists supporting them, she said.
"Blood flowed down a joist and saturated into the timber," the crime scene officer told the jury.
Under the kitchen, officers found a bullet that allegedly killed Mr Baird, with impact damage and a small blood stain.
The bullet travelled through a source of blood before penetrating the wooden floor, Sen Sgt Lansley told the jury.
Investigators also discovered evidence of more bullet damage less than two months before the trial began during a final sweep of the house, the investigator said.
A stick-on plastic hook covered a repaired bullet hole in the bedroom door that wasn't found until July, the jury heard.
Receipts tendered earlier in the trial shed light on Lamarre-Condon's cleaning of the Paddington house after the men's deaths.
Between February 19, the day the two men were killed, and February 23, Lamarre-Condon made 10 transactions at four Bunnings stores totalling $1448.71.
A bucket and mop, disposable gloves, tape, cable ties, bleach and garbage bags were purchased by the officer in his first trip to the hardware store, four hours after he allegedly murdered the two men.
Lamarre-Condon's actions to clean the house did not show he intended to kill the two men, his barrister said in his opening statement.
"The conduct of the accused ... (was) not the actions of a man who believed he was guilty of murder, but a man who panicked considerably," John Stratton SC said.
Sporting goods were also part of the officer's haul through three trips to Decathlon sporting stores.
Lamarre-Condon bought a surfboard bag with a friend two days before the shootings, a purchase captured on CCTV and played to the jury.
But the officer bought another surfboard bag in the hours after the two men died, an action prosecutors say indicates he was forced to adapt to the unplanned killing of Mr Davies.
The trial continues.
20°C