A teenager has been convicted of attempting to rape a woman after he barged into her home and attacked her.

Daniel Williams, 19, of Venners Water, Didcot, was convicted of attempted rape and trespass with intent to commit a sexual offence, following a trial at Oxford Crown Court on Tuesday.

After the verdict was returned, Neil Moore, prosecuting, revealed Williams had been jailed for four years in 2002 for a previous sexual assault and a robbery.

The court heard Williams entered the home of his 23-year-old victim, who cannot be named for legal reasons, on the night of Monday, November 7, last year.

Neil Moore, prosecuting, said: "This is a man who preyed on that woman, a young, small framed lady, a vulnerable lady.

"She was followed home and sexually attacked in her own home.

"He (Williams) got a little bit more than he bargained for and was left with scratches on his neck, which in some way he had to explain.

"He made sexual comments, and was trying to take her upstairs."

When he was arrested Williams told police he had gone to the woman's house for consensual sex, but ran when she turned on him.

Giving evidence in court, Williams changed his story, claiming he had intended to rob the woman, but lost his nerve and ran away.

Pc Terence Kipling said he spotted Williams at 11.10pm, after the woman had reported the attempted rape.

Pc Kipling said: "He (Williams) said 'I'm on the phone to your lot, she scratched my neck.

"He pulled his clothing from his neck and I could see scratches."

A transcript of a 999 call made by Williams, which was read out in court, said: "I went to a girl's house, she went crazy at me, scratching me.

"I'm with the police, she screamed rape and I'm scared."

In a police interview read out in court, Williams claimed he had walked in and the woman had changed into a silk nightdress.

In the interview Williams said: "I said 'that's nice' and she started screaming 'get out, get out'. She started ripping at my neck."

Giving evidence in court, Williams admitted he had told police a "pack of lies".

He said: "I needed to get money, I thought there was no one else in the house at the time."

He said he owed £400 rent and £30 to a friend he had borrowed money from to buy drugs.

He admitted taking cocaine and smoking cannabis before the attack.

After the guilty verdicts were returned, Mr Moore revealed Williams' had previous convictions for theft, criminal damage and possession of an offensive weapon.

He said in 2002 Williams was sentenced to two years in a young offenders' institution for robbery and indecent assault on a charity shop assistant in Lincolnshire.

He said: "One afternoon he entered the shop and locked the door behind him.

"He struggled with a shop assistant, exposed himself, ripped the victim's skirt, removed her tights and underwear and attempted to have sexual intercourse with her. He stole cash."

Williams was remanded in custody, to be sentenced on July 28.