Beau Lamarre-Condon gives tips on how to commit murder

He will step back into the witness box for a final day of questioning at his NSW Supreme Court trial on Monday.

The former officer says he was over Mr Baird romantically but wanted to retrieve shirts, a surfboard and a Cartier ring when he disguised himself as an Uber Eats driver on that fatal day.

During his cross-examination, he insisted he was innocent of murder, saying that if he had actually intended to kill, he would have done things differently.

The men were shot with Lamarre-Condon's Glock sidearm.

He said his work with youth gangs in the NSW Police Youth Command meant he could have obtained a different firearm for $10,000.

He said he would have turned up with a stolen van and cleaning equipment.

Instead, he used a hire car rented in his mother's name and had to buy hardware and cleaning equipment after the two men died, he said.

He also said what he would have done differently with his mobile phone.

"I would not bring a phone or any electronic device to a crime," he told the jury.

Lamarre-Condon and Mr Baird dated from December 2022 until they broke up in April 2023 when the latter could not commit to an exclusive relationship.

The pair started seeing each other in September for two more months.

Mr Baird ceased contact after discovering the then-officer had deleted contacts from his phone and posted fake social media updates.

Prosecutors claim Lamarre-Condon remained jealously obsessed with the TV presenter when he staked out his Paddington home and then executed him.

They allege he shot Mr Davies through the door to eliminate a witness.

The 31-year-old says he accidentally shot Mr Baird during a scuffle after he came at him with a knife.

He claims Mr Davies grabbed the pistol and shot himself during a separate struggle.

He tried to submerge the men's bodies in a dam southwest of Sydney and later buried them behind a monastery before handing himself in to police.