TV presenter Jesse Baird, 26, and his partner Luke Davies, 29, were shot dead inside the younger man's inner Sydney terrace in February 2024.
Senior Constable Beau Lamarre-Condon has pleaded not guilty to their murders, suggesting the two men died after separate struggles inside the Paddington home.
The sworn police officer, 31, accepts he entered armed with his police pistol and heavily disguised but says he did not intend to kill his former partner.
In footage played on Thursday to the 15-member jury, Lamarre-Condon can be seen arriving in Paddington in a hired Mazda about 6am on February 19, 2024.
After driving around Mr Baird's block a couple of times, the senior constable parked and got out of the car undisguised.
The Crown alleges Lamarre-Condon waited several hours to observe Mr Baird's house and make sure his housemates had left before he went in.
CCTV shows him moving the car a second time and then reappearing dressed in hi-vis clothing, carrying an UberEats paper delivery bag and wearing a motorcycle helmet.
Footage from nearby houses shows the accused officer walking and standing in the surrounding streets for several minutes before finally entering Mr Baird's house about 9.42am.Â
Three gunshots can be heard in audio from one CCTV recording, the first two separated by four seconds and the last 51 seconds later.
After the footage was played, Lamarre-Condon took handwritten notes in the court dock.
The senior constable alleges he acted in self-defence in two violent struggles when the two men died.
But the Crown says Lamarre-Condon entered the house with the express intention of killing Mr Baird and then shot Mr Davies while the 29-year-old called triple zero.
Footage from days prior to the February 19 shooting was also played to the jury on Thursday.
In a February 17 recording, Lamarre-Condon can be seen entering a sports store in Sydney's south with his friend Ethan Lynch.
The senior constable picked up a surfboard bag and held it up for Mr Lynch to assess.
In the video, which had no audio when played, Mr Lynch moved towards the bag as Lamarre-Condon held it against his friend.
Lamarre-Condon returned the bag to the rack, picked up a bigger one and paid for it using the same amount of cash he withdrew at an ATM the day before.
In his opening address, prosecutor Brett Hatfield SC said Mr Lynch was expected to give evidence saying the accused asked him whether he would fit inside.
"I'll grab this one instead, it should be big enough," Lamarre-Condon allegedly said when he picked another bag.
Mr Hatfield alleged Lamarre-Condon bought the surfboard bag to dispose of Mr Baird's body when he killed him two days later
However, the prosecution alleges the senior constable was surprised by Mr Davies during the killings, forcing him to adapt during his efforts to conceal the deaths.
Lamarre-Condon was allegedly captured on CCTV buying a second surfboard bag from the same store the day the two men were killed.
Mr Lynch is also the person Lamarre-Condon allegedly confessed the killings to in the hours immediately afterwards.
Mr Lynch asked how he did it and his friend answered: "With a gun, pew pew," while making a hand gesture of firing a gun, Mr Hatfield told the jury during his opening address.
The officer and Mr Baird dated during the summer of 2022-23, with the latter man viewing it more casually than his accused killer.
Many witnesses, including friends and colleagues of Mr Baird, have told the jury about conversations they had with Mr Baird about his fear of Lamarre-Condon's controlling behaviour.
The trial continues.
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