He said gangs repeatedly vandalised his car, causing £5,000 damage, and threw bricks and eggs at his window.
The retired lorry driver, who suffers from a heart condition, finally “snapped” on Halloween when fireworks rained down on his terraced house in a quiet cul-de-sac in Hertford.
Several rockets exploded against his front window just inches from his gas meter.
Mr Parker, a keen game shooter who holds a shotgun licence, took out his .177 air rifle, marched across the street and confronted a group of eight to ten teenagers who then fled.
But minutes later armed police arrived at his home, surrounded the house and cordoned off the road.
Four shotguns, for which Mr Parker had a licence, and cartridges from his gun cabinet were seized by police, as well as the air gun.
The grandfather-of-four was arrested and taken to a police station where he was given a caution for possessing a firearm with intent to cause fear of violence.
These kinds of stories come out of Great Britain all the time. But they never cease to make me sick.