The incident took place near the unfinished Careenage jetty.
Keron Joseph, 18, was killed after he allegedly attempted to rob group of men while armed with a gun.
One of the men was an off-duty policeman who was also armed.
Both men began shooting at each other.
The teen was injured and run off, but he was collapsed a short distance away.
He died on the scene.
Resident said over grown bush near the jetty makes the area unsafe.