Clinton, a heroin addict who has committed a string of burglary offences since he was 13, entered the jewellery shop wearing a tea towel over his face, brandishing a 12-inch kitchen knife.

He shouted "get down" to manager Ricky Oakenfull and shop assistant, Katie Healy, who fled to a back room where she locked herself in and called the police.

Clinton snatched two Diamond Solitaire rings and a watch before running out of the shop. Two members of the public were praised by the judge at York Crown Court after chasing Clinton through the town.

Postlady, Ellen Chapman, and Alex Dearlove, who was visiting Scarborough with his family on the day of the robbery, both bravely tried to catch the raider.

Alan Mitcheson, prosecuting, said: "Mr Dearlove heard the manager shouting for help when Clinton left the shop. He started chasing him for some distance towards the seafront. As he ran, Clinton discarded items of his clothing, which Mr Dearlove was able to get.

Clinton managed to get away but Mr Dearlove was able to give information to police of the route he had taken. "Mrs Chapman was going about her business when she saw the chase.

She was in Bar Street when she tried to get in his way by stepping in front of him. When he pushed her she tried to grab his arm. "She then started chasing the man but stopped when she was told he had a knife. She suffered minor injuries to her arm."

Clinton was arrested after his DNA was traced from the tea towel. He confessed to the robbery while being questioned by police. He also admitted a burglary at Queen Street where he stole an XBOX console game worth £40.

He told officers he needed to money to pay off his drug debts. Clinton also admitted 12 other offences which included burglaries and thefts.

Judge Stephen Ashurst said: "You have a perfectly dreadful record of burglaries and this knifepoint robbery has been your most serious offence.

"Your behaviour had a huge impact on your victims who were in the shop. The manager has nightmares and both have lost their confidence. The sales assistant said she had never been so scared in her life. In the past you have been convicted of six offences of robbery. You have been put in custody before but this has clearly not made a difference."

Judge Ashurst awarded Mr Dearlove and Mrs Chapman £250 each for their bravery. He said: "He was armed and many other people would have stayed away. I want to award them £250 from public funds.

If it was not for their efforts it may have been that he would not have been brought to justice." Clinton was jailed for six years for the robbery and 12 months for a burglary at a Queen Street property in June.