A gang of 15 teenagers armed with a zombie knife and knuckleduster attacked a woman and her partner in Penhill, a court heard.

Jay Mapstone, 19, was yesterday given 16 months in jail for his part in last year’s brawl and attacking officers at the police station after he was arrested.

Sending the heavily-convicted teen down, Judge Jason Taylor QC said: “You need to understand that if you keep behaving in this way then sentences will invariably be prison and they will get longer. Now’s the time to make the break.”

Swindon Crown Court had earlier heard Mapstone knocked at the door of a house in Shalbourne Close, Penhill, on December 7, 2019. Inside was the mother of a boy with whom he had fallen out.

The teenager was described as agitated, looking for the woman’s son. She called her partner who arrived soon after in a taxi, meaning to take the woman and her son away with him.

They were approached by a group of around 15 teenagers, including the defendant.

The woman was struck, leaving her with a cut to the head, while her partner was punched and kicked to the head.

Other members of the group were said to have had weapons, including a zombie knife and a knuckleduster. In a basis of plea, Mapstone said he was a part of the group but did not have a weapon and was not aware that others were armed.

He was swiftly arrested and held in the police station overnight. The following morning he made threats to harm himself and anyone else who tried to come into his cell.

Mapstone kicked one officer in the back before restraints could be tied around his legs. He tried to bite the same officer, then spat at another officer.

The teenager, formerly of Banwell, Somerset, had been due to stand trial on charges of affray, causing grievous bodily harm, actual bodily harm, threatening another with a blade and assaulting emergency workers, but pleaded guilty on the morning of the trial to the affray and assaulting officers. Formal not guilty verdicts were recorded by the judge on the other matters.

He had a poor criminal record despite his young age, with 16 convictions for 27 offences. He was subject to a conditional discharge at the time of the December incident.

Chris Smyth, defending, said his client had always denied having a knife. He had been remanded in custody since March. “It’s his first time serving a sentence of this sort and we will see at the age of 19 what impact that has on him; hopefully a good one in terms of realising he can’t behave in the way he has done.”