Five boys who spat and swore at a 67-year-old father before pelting him with stones wept yesterday as they were found guilty of causing his death.

Aged between 10 and 13 at the time of the offence, the gang members attacked Ernest Norton as he played cricket with his son James.

Two stones, one the size of half a brick, struck the former engineering draughtsman on the temple and fractured his cheekbone. He collapsed to the ground with a heart attack.

The five boys, now aged between 12 and 14, clung to their parents after they were convicted at the Old Bailey of manslaughter and violent disorder. However, they had spent the day “hell bent” on causing trouble when they attacked Mr Norton, according to one detective.

The case, which included some of the youngest defendants ever tried at the Central Criminal Court, has concluded amid a national debate over the violent conduct of some children.

Damaris Lakin, the Crown Prosecution Service lawyer, said: “It high-lights the need for young people in gangs who engage in antisocial behaviour to accept responsibility for the consequences of their criminal activities.”

The attack happened in February last year after Mr Norton, his wife Linda and his son had gone to their local leisure centre in Erith, Kent. While his wife went to the gym, he and his son began to play cricket in an outside tennis court.

The pair were surrounded by up to 20 youths, who began to shout insults including “rubbish bowler” and “Go back to the old people’s home”.

Mr Norton tried to scare off the boys by shouting back. The youths, wearing tracksuits and hooded tops, responded by spitting on Mr Norton. Others, including the five defendants, began throwing stones, rocks and pieces of wood.

“They were just laughing,” James, 19, told the court. “I just heard a loud noise behind me and that’s when I turned round to see my Dad collapsed. It was just a thud.”

James ran to get help and inform his mother. When they returned minutes later, an off-duty police constable was trying to save Mr Norton’s life. As Mr Norton lay dying on the tennis court, Mrs Norton rushed to his side, held his hand and spoke to him, she told the court.

“I can’t remember much about it. I called his name and held his hand but there was no response,” she said.

She described how Mr Norton had been a loving husband, who had lost his job 27 years ago, and had doted on their two children. It was a matter of deep regret that he was not alive for the birth of their granddaughter last month, she added. The court heard that Mr Norton underwent a triple heart bypass operation in 1977.

Because of the age of the defendants – two brothers, aged 12 and 13, and three other boys, aged 14 – they sat in the dock with their parents while judges and barristers did not wear wigs and gowns.

The boys belonged to a gang called TNE – short for The New Estate – and earlier that day, armed with a baseball bat, had met up with another group of youths for a fight. They had also smashed windows in a disused factory and had insulted staff at the leisure centre.

The five were remanded on bail to October 19 for presentence reports to be prepared. After they left the court, the defendants fell into the arms of their parents. Mrs Norton, who had looked relieved as the verdicts were delivered, left the court in silence.

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