A TEENAGER faces at least 11 years in jail after being found guilty of murdering good Samaritan, Liam Attwell, who went to the aid of a group of Chippenham youngsters.

A jury at Bristol Crown Court took 11 hours on Tuesday to unanimously find Brian Grady, 17, of Lincoln Street, Barton Hill, Bristol, guilty.

As the jury foreman returned the verdict Mr Attwell's mother, Roisin Reddick, punched the air from the public gallery, while distraught members of Grady's family left the court.

The court heard Mr Attwell, 25, died after Grady stabbed him through the heart with a three-inch blade last October.

Mr Attwell had intervened when he saw Grady and other youths mugging three Chippenham boys who had gone to the city skateboarding. They had taken one of the boys' mobile phones.

Sentencing Grady, the judge, Justice Brian Keith, told him: "Your actions left the city of Bristol in shock.

"The life of a young man courageously doing his civic duty had been cruelly brought to a premature end.

"There is only one punishment for what you did and since you were only 16 at the time you will be detained at Her Majesty's pleasure without a release date."

He said the jury's decision meant the death of Mr Attwell was no accident.

He said Grady's grandfather, who had given him the knife, should look at his own conscience.

Offering condolences to Mr Atwell's family, he said: "His life may have been a short one but at least his family knows he died courageously, doing his duty as a citizen.

"He will not be forgotten.

"I hope this trial goes some way to help them come to terms with the tragic loss."

Grady pleaded guilty to conspiracy to rob and also received a four-year jail sentence to run at the same time.

Three other teenagers have also pleaded guilty to conspiracy to rob and will be sentenced shortly.

After the hearing, Mr Attwell's mother Roisin, 46, of Redland, said: "I will never regret what Liam did. I just regret that he's not here.

"We feel his honour has been satisfied. We had people tell us of their admiration for what he did and, if his actions prompt other people to stand up for what they believe in, we feel his death won't have been in vain."

Detective Chief Inspector Neil Smart, of Avon and Somerset CID, said: "I am very pleased with the verdict.

"Liam Attwell lost his life by intervening in a street robbery in a very public-spirited and brave manner.

"I am very pleased for his family that justice has been done here today."