A HEROIN addict is beginning a 13-year prison sentence for robbing a post office and a petrol station, during the first of which he beat a man unconscious with a metal bar.

Daniel Carpenter's attack on the 55-year-old, who was sorting papers at the Crumlin Post Office on Saturday September 9 last year, was "savage and wholly unnecessary", and "chilling" in its lack of emotion, said Judge Stephen Hopkins.

In a statement read during a sentencing hearing at Newport Crown Court, Carpenter's victim said he had subsequently suffered headaches, which persist seven months later. He has also lost the hearing in his right ear, has had to give up his role delivering newspapers from the post office, and now rarely goes out.

Carpenter, 36, of Load Of Hay Road, Crumlin, stole around £1,000 in cash during the raid, after also threatening a member of staff with the bar.

And a little more than two months later, he and an unidentified accomplice robbed the Albion Road Service Station in Pontypool, armed with a metal bar and a knife respectively, threatening a staff member before stealing cash and cigarettes with a total value of around £500.

Following the latter robbery, Carpenter reported stolen the Vauxhall Astra car - his father's - that he had used to get to and from both robberies. It was subsequently found burned out near Trinant.

Carpenter - who had been arrested over the post office robbery and released pending further inquiries prior to committing the petrol station robbery - was arrested again after he went to Blackwood police station to inquire about the car.

He was linked to the robberies by his clothing and by telephone activity that placed him at the scene of one of them, but denied all involvement.

He pleaded guilty to two charges of robbery, one of arson, and one of perverting the course of justice, only shortly before a trial was due to start.

Defence counsel Hashim Salman said a heroin addiction that has "plagued" him for 20 years is at the heart of Carpenter's history of offending. He has 10 previous court appearances for 18 offences including assault and burglary, though nothing since 2010.

Mr Salman said Carpenter had "spiralled out of control on a path of self-destruction" and had overdosed after the first robbery, requiring several days in hospital.

Judge Hopkins said CCTV footage from the post office robbery "demonstrates vividly" that the man Carpenter attacked was unconscious for some time.

"It was savage and unnecessary violence you used on him, and it has a continuing effect upon him," said Judge Hopkins.

"He said that what happened has changed his life completely, and you are responsible for that."

He added that the petrol station robbery had also been a "terrifying experience" for the member of staff involved who, though he had returned to work straightaway, subsequently felt paranoid if he saw people wearing hoodies, and had become stressed and anxious at the thought of having to attend a trial.

Carpenter was sentenced to nine years' in prison for the post office robbery, and four years for the petrol station robbery, 13 years in all. Sentences totalling 14 months for arson and perverting the course of justice will run concurrently.