Four police officers accused of lying over the shooting of Adam Salter in 2009 have walked free from court after they were found not guilty of giving false evidence to the Police Integrity Commission (PIC).

Adam Salter's father said he thought he had been tasered, rather than shot. ( ABC News: Luke Rosen )

Sergeant Sheree Bissett put her head in her hands and sobbed as Justice Greg Woods delivered the not guilty verdicts in the Downing Centre District Court today.

Fellow officers Emily Metcalfe and Aaron Abela comforted Ms Bissett, while officer Leah Wilson wiped away tears.

The Crown alleged the four officers "got their heads together" and agreed to lie in the PIC about the circumstances that lead to the fatal shooting of Mr Salter, who had a mental illness, in 2009.

In handing down his judgement, Justice Woods said the charges had not been proven beyond a reasonable doubt.

"In my view, false swearing is not proven," he told the court.

Sergeant Sheree Bissett (back right) arrives at the Downing District Court ahead of her judgement. ( ABC News: Jessica Kidd )

Mr Salter was fatally shot at his father's house at Lakemba when the four police officers were called to intervene after he began stabbing himself in the neck with a knife.

The officers each maintained Constable Abela tried to physically restrain Mr Salter when he reached for the knife a second time and began stabbing himself, just moments before Sergeant Bissett entered the kitchen and shot Mr Salter in the back.

Aaron Abela was trying to restrain Aaron Salter when he was shot by another officer. ( ABC News: Luke Rosen )

Three paramedics who were treating Mr Salter, along with his father Adrian, all gave evidence they did not see Constable Abela restrain Mr Salter.

Justice Woods told the court the police, paramedics, and Mr Salter's father were confronted with a chaotic and frantic scene and that "these factors made it difficult for most, if not all, witnesses to accurately recount what happened".

"I do not regard those inconsistencies as sinister," he said.

"I think it probable that Aaron Abela did move and it cannot be ruled out that he did make contact with Adam Salter in some form.

"Regrettably, we cannot press a button and playback these events."

Importantly, Justice Woods said he found the witness evidence of Adrian Salter to be unreliable, saying his perception of the shooting was clouded by his grave concern for his mentally ill son.

"To see his son stabbing himself with a large kitchen knife must have been traumatic," he said.

"It is clear Mr Salter's distress would have made it difficult for him to perceive the events with accuracy and clarity."