Homicide police will allege Mr Starling was an innocent man caught in the middle of a deadly dispute between the Rebels bikie gang and an organised criminal on the state's central coast last July.

On Friday police arrested the president of the Rebels outlaw motorcycle gang's Windsor chapter and charged him with murder.

It will be alleged that John Weston shot Mr Starling in the stomach and left him dead and and slumped over the wheel of a vehicle outside his West Gosford car repair and customisation business, the Chop Shop.

"Laurie was targeted because he was the friend of an organised crime figure and he was holding the property of the organised crime figure," Detective Inspector Grant Taylor said.

Police said they had a clear picture of what had happened and were homing in on the person responsible for organising the killing.

"We are pursuing those who organised it...pursuing a third person," he said.

Witnesses heard a hail of gunshots and told police they saw three men running from the area before getting into a hatchback parked in a nearby street on July 24 last year.

Mr Weston, 35, was arrested at Kingswood in Sydney's western suburbs and was expected to face Penrith Local Court on Friday afternoon charged with murder.

In April this year, a 29-year-old man was arrested at a property in South Windsor and charged with murdering Mr Starling. He remains in custody.

Mr Starling was heavily involved in the modified car, truck and bike industry and was a judge for the Summernats car festival in Canberra.

At the time of his death his father, Robert Starling, who moved to Australia from Colorado with his son 15 years ago, said it was difficult to comprehend the loss of a "compassionate human being and a fine son".

He said his third son always wanted to help people and was a mentor to many.

"He always wanted to leave something better than he found it," he said.