THE sister of a teenage girl killed in a horrific attack has spoken of her anger following the killer’s escape from an open prison.

Richard Hanson, then 21, was locked up for life after slashing 18-year-old Gemma Roberts’ throat with a broken bottle near a pub in Liversedge in September 2006.

Hanson, who was branded a “very dangerous young man” by the judge, absconded from HMP Thorn Cross, an open prison in Cheshire, last Friday afternoon.

Police urged people not to approach Hanson, who has links to Huddersfield, Dewsbury and Oldham, but to call 999 if they see him.

Gemma’s sister Leanne Roberts, 38, from Batley, spoke of the moment she and her family received the news.

She said: “I felt sick, sick to my stomach. My mum has done nothing but cry.

“It’s like a kick in the teeth.”

Leanne spoke of how it had taken a huge and devastating toll on her mother.

“It’s taken too much out of her,” she said.

“It’s been 15 years, it’s three weeks off her anniversary. It’s quite a big anniversary, we’ve just had her [Gemma’s] birthday in August, then this, it’s not a good time for us anyway," she said.

On top of the fear that Hanson could be in the area, prompting the family to take the step of having alarms fitted, Leanne said the family were not made aware he was in an open prison.

She said: “It’s just brought everything back, everything is really fresh.

"It's made it feel as if it's yesterday."

“I think maybe somebody is hiding him, I think they should do the right thing," she added.

“He should either hand himself in or if somebody knows where he is, they should be alerting the police.”

Hanson admitted Gemma’s manslaughter on grounds of diminished responsibility.

The court heard he had displayed psychotic behaviour since he was aged three and attacked Gemma, a total stranger to him, as he walked past her in Holme Street.

Bleeding profusely, Gemma staggered into the car park of the Swan Hotel in Bradford Road where staff and customers desperately tried to save her life.

She was taken to Dewsbury District Hospital but despite resuscitation attempts was tragically pronounced dead.

Judge Peter Collier told Hanson: "It may never be safe to take the risk of releasing you."

He said the killing was random and meaningless and added: "You are a very dangerous young man. Gemma Roberts was walking down the street. You randomly and brutally robbed her of her life. Not only did you cut short her life you devastated the lives of her family.

"Her death was the culmination of several weeks in which you were getting increasingly out of hand. Eventually, on September 21, you were threatening almost everyone who passed you on the street and attacked several with a broken bottle in your hand.

"At the time of the killing you were suffering from a long-standing severe personality disorder and that seriously impaired your responsibility for your actions."

In a victim impact statement Gemma's mother Mrs Tracey Roberts said her daughter had died senselessly. Before her death she was the happiest she had seen her.