Timothy Baker was a leading senior constable when prosecutors allege he murdered Vlado??? Micetic???, a motorist the policeman pulled over in Union Street in Windsor on the night of August 25, 2013, when he saw the driver's car had stolen number plates.

The Supreme Court has heard the two men struggled when Mr Baker tried to arrest Mr Micetic, and that the policeman fired three shots. Mr Micetic, 44, died in hospital.

Mr Baker, 46, has pleaded not guilty to murder. He claims he saw Mr Micetic pull a knife during the struggle and shot him in self-defence.

Prosecutors allege Mr Baker planted the knife after he shot Mr Micetic.

His trial was on Monday told a sound expert had identified the sound of a flick knife being opened in the 22 seconds after the shots. The sounds were captured by a digital recorder on Mr Baker's protective vest.

But defence counsel Ian Hill, QC, addressing the jury on Tuesday, said another sound expert had identified the sound of a flick knife being opened about two seconds before the first shot, when Mr Baker and Mr Micetic were struggling.

Mr Hill said the statement Mr Baker made eight months after the shooting "eloquently and clearly" identified his self-defence reasoning.

In the statement, Mr Baker said he saw Mr Micetic pull a knife and that he had a "crazed look in his eye", and that the policeman of 24 years' experience feared he would either be killed or seriously injured.

"I went for my gun thinking I was going to be stabbed," he said.

The policeman said he was scared even after he shot Mr Micetic and so moved the knife away from him.

Mr Hill said investigating police later found five knives in Mr Micetic's car, including two that were "strategically placed" near the driver's hand. Police also found weapons in his home, including a large blade stashed near the front door and a sawn-off shotgun.

The motorist had a blood alcohol reading of 0.14 and tests showed he had methamphetamine in his system, the court heard.

Mr Hill said the evidence would show Mr Micetic had a long-standing history of erratic and aggressive behaviour, especially when under the influence of drugs, and that he had convictions for dishonesty and violence offences.

The policeman was working alone - "one up" - that night on highway patrol duties when he pulled over Mr Micetic, the court has heard, and the struggle began after he put a handcuff on the motorist. At that point, a woman in Mr Micetic's car got out and walked away. She did not see the shooting, the trial has heard.

Mr Hill questioned why Mr Baker would call out to the woman not to leave if he intended to shoot Mr Micetic, and disputed prosecution claims the officer "bundled" the motorist towards the front of his car, out of sight of the camera in the police car behind.

"It was a dance between two, which would not have happened had Mr Micetic not attempted to move away from the direction" where the woman was walking, Mr Hill said.

The first witness, Detective Senior Sergeant Stephen McIntyre, showed the jury Mr Baker's vest, the extendable batons and capsicum spray canisters police carry, and the firearm safety flag that denotes when a pistol chamber is empty. The trial heard a flag was found at the scene.

The trial continues before Justice Christopher Beale.