Three men charged with murder over a gun battle in Sydney's south-west say they acted in self-defence.

Darren Troy Moulds, Darren Michael Hoskins and Michael Patrick Brown have all been charged over the death of Jamie Lefoe at Ruse in January 2011.

The men say they were acting in self defence after the victim began shooting at them.

A fourth man, Sean Robert Sutcliff, has pleaded not guilty, saying he was not involved in the violence.

Mr Lefoe died after being beaten, shot and stabbed during an argument over a car.

Prosecutors allege the four men chased Mr Lefoe down and attacked him after he pulled out a gun and shots were fired.

In the New South Wales Supreme Court today, the jury was shown graphic photographs of the crime scene and the knife that allegedly inflicted the fatal wound.

His mother was visibly upset outside court today, yelling at the accused men's supporters as she was comforted by her family and friends.