Three Bradford teenagers have been found guilty of carrying out a humiliating sexual assault on a vulnerable 13-year-old girl and photographing her semi-naked body as she lay unconscious after downing most of a bottle of neat vodka.

A 15-year-old boy and two girls, aged 14 and 15, will be sentenced at Bradford Crown Court in about a month’s time.

All three were yesterday afternoon convicted by a jury of sexually assaulting their victim in a field in Queensbury on December 22, 2011.

They were each also found guilty of taking indecent photos of the comatose girl, after her clothing was ripped off and she was covered in mud and grass.

The 15-year-old girl was convicted of distributing some of the pictures by sending them to another boy.

Judge David Hatton QC directed the jury to clear the three of assault by penetration. The teenagers, who cannot be named, were visibly shaken and upset outside the courtroom after the verdicts were delivered.

Judge Hatton asked the Youth Offending Team to prepare a report on all three before he sentences them on a date to be fixed.

They were all re-bailed with the condition that they do not contact, or try to contact, the victim and her family.

Judge Hatton said he wanted to know more about the abused girl and her family.

He told the defendants: “You have each been found guilty of offences of sexual assault and the taking of indecent images and, in each of your cases, I am going to adjourn sentence.”

During the trial, prosecutor Nick Askins accused the teenagers, who were 13 and 14 at the time, of abusing the comatose girl to entertain themselves in the school Christmas holidays.

He said that sexually humiliating the troubled and vulnerable girl was a particularly unpleasant incidence of bullying. She was unhappy at home and at school and had taken Paracetamol tablets because she wanted to end her life. The defendants told the jury the girl downed most of a bottle of vodka and was spinning round to get drunk quicker. She fell over and was “out of it” on the ground.

She was moved into different positions as they all took pictures of her on their phones for “a laugh”, the court was told.

The boy stored his in a file called “Lasses” on his phone.

The girl was taken by ambulance to Bradford Royal Infirmary where it took her about six hours to come round. She recalled nothing of the incident.