Advances in DNA testing led to the arrest of a convicted sex offender on suspicion of carrying out knifepoint attacks on two young women over 26 years ago, a court heard.

The women were the victims of separate assaults by a masked man in car parks in Gravesend and Chatham in July 1990, but an arrest was not made at the time.

They remained “cold cases” until 2015 when police were able to link DNA evidence to John Clayson, who was jailed for five years in February 1995 for attempting to rape a woman in Cornwall at knifepoint.

Prosecutor Christopher May said the police had looked back to see what could be done using more modern scientific techniques.

Forensic experts were able to make a match from a stocking worn on the attacker’s head to Clayson’s DNA profile.

The former baker, now 60, of Upper Fant Road, Maidstone, denies attempted rape, indecent assault and having an offensive weapon in relation to one of the women and false imprisonment, indecent assault and another serious sexual offence in relation to the other woman.

He also denies committing three other serious sexual offences with another woman.

Mr May said the first attack was on a 19-year-old woman on the top floor of a multi-storey car park at The Pentagon shopping centre in Chatham on July 4, 1990.

The second attack was 16 days later on a woman, 21, at the former Anglesea multi-storey car park, now Thamesgate shopping centre, in Gravesend.

Clayson was at the time living in Dagmar Road, Chatham, and working at a bakers in Denton, Gravesend.

Mr May said more recent scientific tests found the majority of Clayson’s “components” present on the stocking. There was a mixed profile and showed it was 13 million times more likely that the DNA came from Clayson and one or two others.

He was also alleged to have committed serious sexual offences with a third woman.

On one occasion he held her penknife to her throat so that he could commit the offence, it was alleged.

When arrested in July 2015, Clayson denied he was the attacker. He claimed he was “fitted up” by the police for the attempted rape in Cornwall.

Mr May said the alleged victim of The Pentagon shopping centre attack had just parked her car in the afternoon and was going to the lift when she was confronted by a stranger wearing a biker’s jacket and with a stocking with holes in over his head.

He grabbed her arms and pushed her against a wall. He stroked her mouth and face as she begged him not to hurt her or rape her.

She offered him money but he gave it back to her. He put away the knife he was holding and put his hand inside her jacket.

He groped her and started to put his fingers in the top of her jeans but he was disturbed by the arrival of the lift. He then made off.

“The Crown say if not for that he would have gone on to what he intended to do,” said Mr May.

Two women took the distressed teenager to where her mother was working and the police were called.

16 days later, at the former Anglesey multi-storey car park, a 21-year-old woman had been shopping and was heading back to her car when a masked man jumped out on her and told her to be quiet.

Mr May said the man told her he was not going to hurt her. He grabbed her by the throat and told her to get into her car.

She got into the passenger seat and he sat in the driver’s seat. He tied her wrists with a pair of tights and put a plaster over her mouth. He warned her he had a knife.

He tried to drive her away but could not handle the car. He then pulled down her knickers and molested her before committing a serious sexual offence.

Afterwards, he ran off. She managed to drive away and while doing so saw her attacker again. He had taken the stocking off his head and was in a car.

She took down what she believed to be the registration number. Police found a stocking which was later analysed for DNA.

Despite telling officers the registration number, the attacker was not traced. But years later a photo was obtained showing Clayson standing by a car with a number plate that had one letter different to that given by the victim.

The trial continues.