Click play for video report, including footage of car park chase.

Images have been released as part of an investigation into two shootings, one of which has left a teenager disabled for life.

The Cheltenham victim, 19, was dropped off at Knox Private Hospital with critical injuries in August.

Police say he was shot during an altercation at a shopping centre carpark in Vermont South.

CCTV (above) shows two cars chasing a third car.

The two chasing cars – a gold Holden ute and dark blue Commodore – were spotted earlier at a petrol station lying in wait for the victim.

The ute has been recovered.

An 18-year-old was released pending further enquiries.

A face image (in above video) has been released of the suspected gunman who is also believed to have attempted to shoot a man in broad daylight in Surrey Hills in May.

Police are urging a person who called Crime Stoppers in September to call again, as well as anyone else with information.