Man behind bars after Sydney grandfather allegedly shot in unprovoked attack

A man is behind bars tonight after allegedly shooting a Sydney grandfather in the neck in a random, unprovoked attack.

A 69-year-old man was completing a three-point-turn around 9pm last night after dropping off a family member at Whitcroft Place in Oxley Park when it's alleged a shot was fired from a backyard 30 metres away.

The bullet shattered the back rear window of the man's car, whistled between two passengers, and struck the man in the neck.

He was taken to Nepean Hospital for treatment.

His family and friends confronted the alleged gunman after the incident.

"You just shot someone in the back of the neck...he's got something mate, he's got something on the back of his neck," a voice can be heard saying in footage taken shortly after the incident.

Police allege the shooter is a 24-year-old neighbour.

Police also allege the man takes the illicit drug ice and was in possession of a firearm for "protection".

The man was refused bail and appeared in Parramatta Bail Court today.