The stray bullet struck Bob Knight, 66, in the head as he drove along Milperra Road on the night of June 25, 2009, completely oblivious to the gunfight taking place between two groups of men 120 metres away.

Three of those men - Mahmoud Mariam, 28, Adel Elkobali, 21, and a juvenile who cannot be named - are now on trial for murder and affray in the NSW Supreme Court.

In the first day of the trial yesterday, Crown Prosecutor Pat Barrett said that the two groups of men - who were allegedly connected to the Elkobali family and the Mariam family - drove to the KFC car park in Milperra with the intent to case ''serious bodily injury''. Teenage members of the two families had clashed earlier that night at the Centro Shopping Centre in Bankstown, he said, and the two groups allegedly arrived at the KFC car park armed with guns and other weapons.

Mr Barrett said the shot which killed Mr Knight was fired by Mahmoud Mariam.

''The bullet travelled out of the car park, through the trees, across the road and hit him in the truck,'' Mr Barrett said. ''None of the accused intended that Bob Knight was to be killed … But that's irrelevant.''

He said that because the three men were involved in a joint criminal enterprise in which they or their associates were armed and intended to cause ''very serious bodily harm of injury'' they could be found guilty of murder.

But counsel for Elkobali, Michael Pickin, said that his client should not be held responsible because he neither fired the fatal shot, nor initiated the gun fight. ''Mr Knight's manner of death remains both a tragedy and an outrage,'' Mr Pickin said. ''But I do ask you to be detached, clinical and dispassionate.''

He asked the jury not to be affected by the ''stereotypes'' associated with youths of Middle Eastern background when looking at the facts. ''It's not in dispute that my client was present. What is in dispute is that he discharged any firearm … He did not use, discharge or own any firearm.''

The trial continues.