A Wallington man who shot a shop manager during an armed robbery should have been in jail when the crime was committed, it has been revealed.

Sean Henry, 35, of Douglas Close, was sentenced to a minimum of 15 years for attempted murder, robbery and possessing a firearm after he stole diamond rings worth £50,000 from Amore jewellers in Horsham.

During the robbery he shot manager Darren Prior, who only escaped death because a mobile phone in his pocket absorbed the impact of the bullet. He also threatened to shoot shop assistant Christopher Purvis.

It has now emerged that just 13 months before carrying out the robbery in September 22, 2005, he had been released on licence after serving 13 years for murder.

If the advice of the Probation Service had been followed he would have been transferred to an open prison for at least another two years before being released.

The decision to release him early was made by the parole board who have now apologised to the victims for the blunder.

The parole board's head of communications, Tim Morris, said: "The parole board regrets the circumstances that led to the attempted murder of a jewellery shop manager by Sean Henry."

"The board wishes to convey its sympathies to the victim and his family for the trauma they have suffered. We are committed to doing everything we can to learn the lessons from such cases that will help to prevent further such incidents."

Henry was jailed in 1990 for kicking and beating a person to death when he was just 17.

He was released on licence in August 24, 2004, following a parole board review of the case.

A report by the probation and HM Prison Service said he should be tested in a category D open prison first, but the board opted to release him.

Henry and his getaway driver Timothy Cole, 30, of Crawley were caught after a prison officer recognised Henry on a BBC Crimewatch appeal.

After the case, the parole board established a Joint Review Panel to consider instances where serious further reoffending has taken place.

Mr Morris added: "Since this case took place, the Board has formally adopted a policy that the release of an indeterminate sentence prisoner from closed conditions should only take place in exceptional circumstances."