Beau Lamarre-Condon has pleaded not guilty to the murder of Mr Baird, 26, and his new partner Luke Davies, 29, claiming he acted in self-defence during separate struggles with the men.
On Wednesday, a close friend of Mr Baird tearfully recounted how close his mate and Mr Davies became before the fatal incident in February 2024.
"He was almost falling in love with him," friend Matthew Edwards said in court on Wednesday.
"I've never seen Jesse as happy.
"There was something about Luke that just lit Jesse up - they were the real deal."
Members of Mr Baird's family became visibly emotional in the public gallery of the NSW Supreme Court during Mr Edwards's testimony.
The friend gave evidence about conversations in which Mr Baird expressed how relieved he was to have cut contact with Lamarre-Condon in the last months of his life.
"Once I move house, this will be the last piece of me Beau knows," Mr Baird allegedly told Mr Edwards about a fortnight before his death in his Paddington home.
When Mr Edwards asked whether he had heard from Lamarre-Condon recently, he recalled Mr Baird responding: "No, thank f***."
Under cross-examination from Lamarre-Condon's barrister, Mr Edwards said posts the police officer made on Instagram lying about his relationship with Mr Baird did not rise to his friend being worried about his safety.
"Words 'unsafe' coming from Jesse, no," Mr Edwards said.
"Uncomfortable, yes."
Defence barrister John Stratton SC has told jurors that Lamarre-Condon did some "stupid things" to Mr Baird but his behaviour was never threatening.
Prosecutors contend Lamarre-Condon's preparation for the killings and subsequently disposing of the bodies amount to murder.
But the senior constable's barrister says moving the bodies is a demonstration of a panicked man who acted in self-defence.
Lamarre-Condon has suggested his gun went off twice while struggling with Mr Baird, killing the 26-year-old, while Mr Davies shot himself while later wrestling the police officer.Â
Later in the trial, the jury of 15 men and women is expected to hear from the officer's close friend about a conversation the pair had straight after Lamarre-Condon left Mr Baird's house on February 19, 2024, prosecutor Brett Hatfield SC said.
After arriving in a car he hired in his mother's name the day before, Lamarre-Condon asked Ethan Lynch to not judge him for killing the two men.
When his friend asked if he was joking, Lamarre-Condon allegedly responded: "I wish I was."
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.
Lamarre-Condon allegedly said that after hearing a noise of a second person - Mr Davies - in the bedroom trying to make a triple zero call, he shot them through the door.
"Couldn't take the risk ... no witnesses," he allegedly told Mr Lynch.
Mr Lynch later gave statements to police about what Lamarre-Condon told him but continued to visit the officer in custody for months after the killings.
Mr Stratton alleged it was his client who attempted to call emergency services after accidentally killing Mr Baird when Mr Davies violently confronted him.
But prosecutors argue there is evidence Lamarre-Condon planned to murder Mr Baird but was forced to adapt to the extra killing of Mr Davies.
He allegedly bought one surfboard bag at a sport store after testing if it would fit an adult inside with Mr Lynch two days before the killings.
Shortly after his "pew pew" discussion with Mr Lynch, Lamarre-Condon was allegedly captured buying a second surfboard bag.
The trial continues.
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