A shopkeeper has been fined £250 and given a criminal record because he fought back when he was attacked by shoplifters.

Jacob Smyth chased three youths out of his hardware shop in Penzance, Cornwall, when he was set upon. When he was kicked in the groin by one of the hooded youths who had stolen cans of spray paint Mr Smyth hit back.

Police issued fixed penalty tickets to the shoplifters but charged Mr Smyth and a colleague with assault.

Yesterday he pleaded guilty to assault at Truro Magistrates’ Court. He claimed after the hearing that he had been advised to plead guilty because otherwise he could have faced a six month prison sentence.

The court was told that Mr Smyth, a father of three, caught the youths stealing the spray cans in October last year. Two of them turned on him and he was kicked in his groin just weeks after a vasectomy operation. He retaliated and punched 18-year-old Craig Spiller to the ground.

Paul Gallagher, defending, said: “The court can only imagine what they intended to do with that spray paint. He could see the cans poking out of their pockets. He leant forward to get them and at that stage he was set upon.

“He did punch one of them to get him off. In the heat of the moment he kicked him once or twice. Initially he was acting in self defence. Frustration at the situation took over. The lads were interviewed and given fixed penalty notices by police but unfortunately for Mr Smyth ended up in court today.

“He was the one who was trying to do the right thing and get his stolen property back.”

Julian Herbert, prosecuting, said the “aggravating factor” of the case was shop staff “taking the law into their own hands”. Fining Mr Smyth £250 and ordering him to pay £43 costs, Angy Haslam, chairman of the magistrates, said: “The act was aggravated by the fact you kicked the victim on the ground. We feel it has been mitigated because you acted in self defence.”

Speaking outside court, Mr Smyth said: “I did nothing wrong. I was getting a good beating from this lad. I had no choice but to defend myself.

“We get shoplifters all the time – one after the other. We call the police but nothing is ever done. We called them on this occasion and ran after the lads to try and get my property back but then they turned on us. “Am I not allowed to protect my stock and premises from thieves?”

Mr Smyth’s colleague Jason Pascoe, 34, has also been charged with two counts of common assault and will appear in court at a later date.

Times Recommends

• UK regional accents thrive against the odds
• ‘Scarecrow’ wind farms put rare birds to flight
• What an anti-climax: G-spot is a myth