None of the descriptions of the killer of Oxfordshire holidaymakers Peter and Gwenda Dixon matched the man on trial, a jury heard yesterday.

Mark Evans QC, the barrister representing farm worker John William Cooper, aged 66, said they were clearly of a different man.

Cooper, of Spring Gardens, Letterston, near Milford Haven, is accused of shooting the couple to death as they walked the Pembrokeshire Coastal Path in June, 1989.

He is also accused of murdering brother and sister Richard and Helen Thomas at their home, Scoveston Park, in 1985. They had also been shot with a 12 bore shotgun.

Cooper further denies raping a 16 year old girl and indecently assaulting her friend, as well as attempting to rob five teenagers, all on March 6, 1996.

The prosecution at Swansea crown court argue that all the crimes are linked to each other and to Cooper.

Mr Evans, in his closing address to the jury, said the police had various descriptions of the suspect.

Several came from people who saw a "scruffy" man at cash points at the time that Mr Dixon's cash card was used after the deaths but before the bodies were discovered hidden in undergrowth.

He was described as having long, straight hair but only a few days before Cooper had been filmed for an episode of ITV's Bullseye programme and he clearly had curly hair.

One of the teenagers said their attacker had been as "thin as a pole" and the girl who was raped thought he weighed as little as seven stones.

But Cooper's son, Andrew, had told the court that in 1996 his father weighed about 17 stone and around the time of the attacks he had been weighed at a doctors' surgery at 15 stone.

"It is not open to the crown to say these descriptions do not matter," said Mr Evans, who said there was no evidence that a rape had actually occurred. He encouraged the jury to consider sexual assault instead.

Mr Evans said Cooper had been jailed for 16 years in 1998 for 30 burglaries and a violent robbery. Items recovered by police during that investigation were "cold case" tested between 2007 and 2009 using modern forensic techniques and provided evidence which, the crown says, shows Cooper's guilt of the murders.

Mr Evans said Cooper's motivation during the burglary spree was said to have been to steal cash, jewellery and items of value.

What motive would he have had to attack the Dixons, he asked. Two people obviously out walking could be expected to have with them only enough to buy a pint or a light lunch and certainly would not have been laden with jewellery.

Mr Evans said the jury should not rely on evidence of fibres found on gloves inside Cooper's then home and at the crime scenes, or on DNA test results.

There had been, he alleged, cross contamination between the exhibits because of the way they had been handled by the police over the years.

For example, he said, when police laid out hundreds of items suspected of having been stolen by Cooper during the 1990s, the bloodstained rope used to tie Peter Dixon's hands behind his back found its way into the same box.

And in another box, also containing stolen goods, were a pair of shorts displaying the DNA of the Dixons' daughter Julie.

"What possible relevance could they have to an investigation into burglaries?" asked the barrister.

The jury is expected to begin considering verdicts on Monday afternoon.

Cooper denies all the charges.