A failed property developer who carried out an armed robbery at a jewellers after falling into debt has been jailed for five years.

Married father-of-four Paul Evans, 37, spent hours talking to Geoffrey Dean, 60, co-owner of Parker and Dean jewellers in The Street, Rustington, near Littlehampton, before aiming a gun at his head and walking off with two rings worth £21,500.

The robbery, on June 12, 2007, came after Evans, from Barnett's Field, Westergate, near Chichester, snatched a £5,500 diamond ring from Frost Brothers, Montague Street, Worthing, in April.

Prosecuting, Michael Orsulik, said: "Mr Evans went into the shop a number of occasions and showed a lot of interest in particular rings in the window. They said they were for his wife.

"He returned to the shop at around 4.30pm and said he had decided which one he wanted.

"He then took out a gun, Mr Dean was staring down its barrel, and said 'These rings are mine now, so shut up'.

The court heard Mr Dean was about to chase Evans, who then ran out of the shop, but stopped when he remembered that Darren Prior, a Horsham jeweller, was shot in September 2005 after robbers took £50,000 worth of diamond rings.

Mr Orsulik said Mr Dean has suffered sleepless nights and fears being alone in the shop since the incident.

After the case Ian Parker, Mr Dean's business partner, told The Argus: "Evans was very cool, calm and calculated.

"He spent hours talking to Geoffrey. He was very shaken up by what happened.

"There's not much you can do when somebody sticks a gun in your face."

The court heard Evans took the rings after owing more than £20,000 in connection with his failed Spanish property venture.

He had been stabbed in his own back garden and spent seven days in St Richard's Hospital in Chichester in connection with the debts, Evans' barrister Piers Power told the court.

He added that the people he owed the money to waited around the corner from Parker and Dean as he carried out the robbery.

Mr Power added: "He effectively spent the day building up the bottle to do it. He was under a lot of pressure and received numerous phone calls while he was in the shop from the people he owed."

Police arrested Evans on July 8 last year after the officer in charge of the case, Detective Constable Alex Campbell, of Bognor CID, recognised him.

Officers found a black BB gun, believed to have been the weapon used in the robbery, in the boot of Evans' Bentley.

He admitted taking the rings during police interview and later pleaded guilty to armed robbery and asked for the Worthing theft to be taken into consideration.

Evans, who has previous convictions for deception, let out a deep breath, closed his eyes and raised his head to the ceiling as Judge Anthony Thorpe sentenced him to five years.

Judge Thorpe said: "Courts have a special duty to protect vulnerable members of the public and shop keepers are vulnerable from such frightening acts."

After the case DC Campbell said: "This type of crime was a shock to the local community as it is so rare.

"I hope this goes some way to reassuring the public that Sussex Police will fully investigate all serious crime and bring offenders to justice.

"We are pleased with the sentence awarded by the court and we hope that this is a deterrent to others involved in this type of crime."