A masked rapist was tracked down after 14 years when a relative gave a DNA sample in a completely unrelated case. Detectives reopened the investigation into the violent assault in Bridgwater, in Somerset, in 1993 when test results revealed a family connection to the attacker.

More than 4,000 people related to the arrested man were traced and tested before detectives caught up with 42-year-old Geoffrey Godfrey.

Godfrey, now 42, raped the 36-year-old married mother of two after he attacked her as she walked along a canal towpath. Although the rapist’s DNA was recovered from semen samples, Godfrey was not on any data-base.

Only this year after the arrest of a relative were detectives able to draw up a family tree and narrow the search for the attacker.

At Bristol Crown Court yesterday, Godfrey admitted rape, attempted buggery and indecent assault. Judge Julian Lambert, sentencing him to six years in jail, said: “The terror and distress you caused to that lady towers above all else in this case.”

The court heard that Godfrey attacked his victim on a canal bridge in Bridgwater, Somerset, at 1am on April 25, 1993.

Godfrey, wearing a dark balaclava and gloves, grabbed the woman from behind and used one hand to cover her mouth while he raped her.

Martin Steen, prosecuting, said the woman was too terrified to scream for fear of what he might do to her.

Mr Steen said: ”She tried to keep his hands away from her but she failed. Her tights were ripped as he pulled at them. She also became aware her T-shirt had been pulled up.” The victim, in a statement read to the court, said that she was still traumatised by the attack and was afraid to go out at night.

Ian Pringle QC, mitigating, said that Godfrey had a good reputation and those who knew him including his wife and sister found it difficult to believe that he committed the offence.

He said: “He is known in the community as a decent, hard-working individual. He clearly acted all those years ago in a terribly out-of-character way.”

This is the first time Avon and Somerset police have successfully used familial evidence in a cold-case rape investigation.

Godfrey was implicated after DNA from another family member convicted of an unrelated crime was added to the DNA database.

The review of the case began in 2005 and details of more than 4,000 potential matches had to be processed and eliminated to produce the “one in a billion” match.

Tests were performed over a 16-month period and voluntary swabs were obtained from Godfrey in September 2006. The Forensic Science Service in Birmingham took three days to confirm him as the rapist. Detective Sergeant Mike Britton, who headed the investigation, revealed that there were still more than 20 undetected DNA profiles on the database for similar offences He said: “This result sends a clear message to anyone who thinks they have escaped justice for similar offences.

“With every advance in science it is only a matter of time before they, too, are arrested.”

Times Recommends

• Family cuts its waste to one binful a year
• Cameron can learn from Thatcher in 1979
• VAT is back ... and it's confusing