A 15-year-old girl who filmed two teenagers brutally beating a vulnerable man who later died has been sentenced to two years in the first conviction of its kind in the country.

The girl, who cannot be named because of her age, was told by the judge who imposed the sentence that he was making an example of her and that her behaviour was inexcusable.

Gavin Waterhouse, 29, suffered a ruptured spleen and died alone in his bedsit in Keighley three days after he was repeatedly punched and kicked by Mark Masters and Sean Thompson.

The girl filmed the beating on a mobile phone passed to her by 19-year-old Masters.

After the attack she danced to music while the youths boasted about what they had done, Leeds Crown Court heard.

Gavin Waterhouse's parents have condemned the sentence, branding it just a "wrist slap."

advertisement Speaking from their home in Keighley, yesterday, his mum, Christine, 51, and 44 year-old step-father David Wiseman, said they felt the family had been insulted.

Last week Masters, of Parkwood Rise, Keighley, and 17-year-old Thompson, of Parkwood Terrace, Cullingworth, were sentenced to seven years' youth custody and six years' detention respectively after admitting the manslaughter of Mr Waterhouse.

Judge James Stewart QC sentenced the girl, who also admitted manslaughter, to a two-year Detention and Training Order.

Judge Stewart said her part in "this cruel and revolting venture" was to ask the terrified Mr Waterhouse for 40p and film Masters and Thompson attacking him after he refused.

The judge told her: "You all then ran off, leaving fatally-injured Gavin Waterhouse to make his way home where he died, no doubt in excruciating pain, a few days later.

"It's said you only agreed to video because you were fearful your co-accused would think less of you. That hardly explains the dancing afterwards."

He added: "You can excuse many things in the young but nothing can excuse this behaviour,"

The judge said he had received a moving letter from the girl's mother about the way she had been brought up and the "shortcomings of our modern society".

Judge Stewart went on: "It is only by making examples of youths like you that the court can do its best to try and change things.

"Yours was a minor, though nasty, part of this manslaughter. I must not forget you pleaded guilty to taking part in an unlawful killing."

After the sentencing Detective Superintendent Paul Kennedy of West Yorkshire Police's homicide and major enquiry team, said the girl's conviction for manslaughter, by encouraging the attack through filming, was the first of its kind in the UK and sent out a lesson to people encouraging violence in any form.

Det Supt Kennedy said: "We see these cases week in, week out and you can't help but feel sick to death of the mindless violence that people seem to think they are free to use.

"The court today had sent out a message to other young people that you can't get involved with violence, or encourage violence, without being punished.

He added: "We have never used the term happy slapping'. That phrase does not depict what has happened. This has been nothing other than brutal violence.

"The devastation to Gavin's family is not seen by the public or the people convicted. I just hope that young people take notice of what's happened today. If you involve yourself with violence or encourage violence in any way, for example by mobile phone filming, you will be punished by the courts."

Mr Waterhouse, of North Street, Keighley, was attacked as he drank alone behind the Morrisons supermarket in Keighley on September 23 last year.

His attackers sent a film of the beating to friends' mobile phones.

Judge Stewart said they had wanted to have some sport with their victim, who Masters and Thompson had attacked before.

Abbas Lakha, mitigating, said the girl did not know her co-defendants and had no idea that Mr Waterhouse's refusal to give her 40p would result in violence worse than pushing or shoving. He said she was drunk and in the company of two much older men.

Mr Lakha said the girl had chosen to spend time away from home with much older people who were abusing drink and drugs, but a large part of the blame for that had to fall on others in her family.

He added: "From the age of three she had little or no chance at all and grew up in an environment where violence was a common feature, almost taken for granted daily on her mother and on her."

The parents of Gavin Waterhouse described the two year detention training order as like being sent to a boarding school.

Even though they had been warned that it would not be a heavy sentence, they were still shocked.

"The sentence has devalued my son's life, degraded him," said Mrs Wiseman, who also has two other sons, Lee, 34, and Scott, 23.

"All they seemed to be bothered about at the sentence was how she had done with her school work while in custody."

"The justice system has let us down. Gavin's life has been taken from us cheaply and it seems it is just a slap on the wrist." said Mr Wiseman.

Gavin had been bullied and had died for the sake of the 40p the three had demanded from him.

The family was particularly hurt by the defence barrister's claims that their son was drunk at the time of his death when he was in fact returning to his home in North Street, Keighley, from church in Bradford.

And they hit back at claims made in court yesterday that they had threatened the 15-year-old girl's family.

"We went there expecting justice for Gavin and got insults," Mrs Wiseman added.

"The barrister said we have been issuing threats to her mother.

"We don't know her, we don't want to know her, we don't know where she lives or anything about her family. We have not theatened anybody."

Now she had to learn to live without her son for the rest of her life while the three would be released soon and had their whole lives in front of them.

The girl's mother, who lives in Bradford, said she was happy with the sentence. She was hoping to speak to her last night and aiming to visit her at the weekend.

Her daughter had made vast improvements since she had been in custody, she said, and added: "But I can't say about her mental health - that will take a long time to heal.

"I can't find the words to describe how she feels about what happened.

"She keeps thinking about how she is a child and that he was also someone's child. That is hard for her."