A man who subjected a 15-year-old girl to a "terrible ordeal" by grabbing her in an Oxford alleyway and trying to pull her skirt down has been jailed indefinitely.

Married father-of-two Robert Whitehouse, who has several previous convictions for indecent exposure, got hold of the girl as she walked through Back Lane, in Marston, on the evening of July 18 last year.

Prosecutor Kevin Barry told Oxford Crown Court he grabbed the waistband of her skirt and attempted to pull it down, before pushing the girl, who cannot be named for legal reasons, on to her back.

But she struggled and eventually escaped. Whitehouse was later caught after being identified by a police e-fit.

Whitehouse, 41, of Bicester, denied battery with intent to commit a sexual offence, but was convicted by a trial jury in September.

Judge Anthony King said: "This was a terrible ordeal for the girl concerned and a very serious matter regarding safety of the public and women at large."

Whitehouse will serve just under two years before he is eligible for parole. He was also ordered to sign the sex offenders' register and banned from working with children for life.