My sister was beaten to death by her monster boyfriend - I fear he could soon be free

Warning: This story discusses graphic details of domestic violence and death which some people may find distressing

When paramedics found Bethan Callaghan clinging to life with 92 injuries, her boyfriend told them she had been hit by a speeding van.

The severity of her condition meant police had no reason to doubt Terry Andrews' story that she was the victim of a hit-and-run.

But some aspects of his account didn't add up, such as why he had used a wheelbarrow to get her back into the house and waited 14 hours to call an ambulance.

Bethan, who was 20, later died in hospital, with Andrews found guilty of her murder and sentenced to life in prison with a minimum term of 16 years.

This was in 2010, and Andrews is expected to be eligible for parole in May - something which has shocked Bethan's family, who have started a petition, saying it's far too soon for him to be freed.

Her sister Chloe called Andrews a "monster", saying she would fear for her safety if he was released, adding: "Sixteen years is not enough for him, it's not."

The parole board said it cannot comment on individual cases but parole reviews are "undertaken thoroughly and with extreme care" and "protecting the public is our number one priority".

Documentary The Truth About My Murder has revealed the scale of Andrews' brutality, and how forensics were able to paint a picture of his vicious and fatal attack in September 2009.

"I used to say to her 'just please leave him, he's really hurting you'," said Chloe, who was 13 at the time, and said she knew her "better than anyone".

"He took the light away from my sister, who once was full of laughter, who was so kind and cared for anyone."

Andrews, who was 36, claimed that after being hit by the van, Bethan just wanted to lie on the sofa of their home in Mountain Ash, Rhondda Cynon Taf.

However, she eventually became so unwell, he called 999, with the ambulance crew shocked by what they discovered.

"The paramedics couldn't quite believe what they were seeing, they were absolutely horrified," BBC Wales' former crime reporter Penny Roberts said.

"What was really bizarre about this scene was there was not only a young woman barely alive on the sofa, but there was a wheelbarrow in the living room."

On the face of it, Bethan had injuries typically sustained in a car crash, including bruising all over her body and lacerations.

"Her injuries were very severe, two black eyes, her eyes were very, very swollen, her hands and her arms were blackened with bruising," said South Wales Police's investigating officer Dorian Lloyd.

"She also had lots of cuts consistent with having been knocked over by a car or dragged underneath a car.

"And she was covered in black soot and dust."

Andrews, who followed Bethan to Prince Charles Hospital, Merthyr Tydfil, told police a "speeding van" had hit her on a dirt track lane behind their home.

"They tried to resuscitate her 13 times... but it was just nothing," said Chloe.

Looking back, Bethan's mum Gaynor said: "I remember leaving the hospital, I was just on the floor and I was dragging my hair out to feel the pain.

"And after that, I don't know nothing, I just went into a shell."

Bethan, from Caerphilly, was regarded by neighbours as a "lovely girl with a big smile for everyone".

Her relationship with Andrews was described as a "whirlwind romance" as she moved to Mountain Ash within three months of knowing him.

"She just wanted to have a perfect relationship, kids, happy... she just wanted to be loved," said Chloe.

"She'd do anything for me. She treated me like her daughter... she would look after me."

Bethan's home life didn't ring any immediate alarm bells, but house-to-house inquiries cast doubt over Andrews' story.

He told some people Bethan had run out of their home chasing burglars, while he told others she was knocked over while taking rubbish out.

A post-mortem examination revealed Bethan's most serious injuries were to her head, which was matted with blood, twigs and leaves.

An abrasion to the bridge of her nose also suggested a harsh rubbing against a rough surface, while her lips were swollen and bruised, and there was a cut on her mouth.

Forensic pathologist Dr Richard Shepherd said these injuries plus dirt-staining all over her body suggested she had been "forced against the surface of an unpaved road", which could have happened in a hit-and-run.

But there was no evidence of a skull fracture or brain damage typically seen in such cases or grease from a vehicle.

Witnesses described the couple arguing "ferociously" at the Tynte Hotel and Bethan seeming "very distressed" the evening before.

She told a number of people in the pub Andrews had been assaulting her regularly, showed them bruises on her arm and said she was scared to go home with him.

Despite this, nobody intervened, despite one neighbour seeing Andrews kick Bethan twice in the street.

Another heard her say "don't hurt me I'm bleeding".

"It's amazing that no-one stepped forward, or phoned the police, or intervened," said Lloyd.

In the days following Bethan's death, Andrews refused to engage with police and investigators described him as "very angry and dismissive".

He also started behaving suspiciously, such as giving a pair of white trainers to a friend.

But these were handed to the police, with Bethan's blood found on them and DNA confirming they were Andrews'.

To the naked eye, their house was spotless, apart from a recently-used mop.

Investigators said there were no obvious signs of an attack.

But a blood enhancement chemical reagent uncovered a footwear mark and drag mark on the floor.

Scratches on Bethan's back were then found to have been caused by brambles in their back garden, confirming she was dragged along the kitchen floor and outside.

Andrews' story was Bethan had been involved in a hit-and-run and he had found her in the lane.

A neighbour even helped him put her in a wheelbarrow to push her inside.

The "sheer extent and violence" of Bethan's injuries confirmed the cause of her death to be blunt-force trauma to the head, said Dr Shepherd.

However, the post-mortem examination also revealed much older bruising, confirming she had been the victim to regular physical abuse.

Bethan's family had long had concerns about Andrews and what he may be capable of.

Chloe described how he had threatened to kill her dog if Bethan didn't return home while she was out with her mum.

She had also seen Andrews with his hands around her sister's neck.

But being young, Chloe says she followed Bethan's request not to tell their mum, something which she now regrets.

"You can't just get someone out of that relationship, because they know the right words to say to them and they will go back," she said.

During his trial at Merthyr Tydfil Crown Court, Andrews admitted punching Bethan "once or twice", but said he had found her in the back lane after she had fallen down stairs.

Later, he said he had punched her in self defence after she attacked him with a knife.

But with an overwhelming amount of evidence against him, Judge Justice John Griffith Williams called Andrews a "compulsive liar" and described it as a "very brutal murder".

Andrews was given a life sentence with a minimum tariff of 16 years in May 2010.

"I still don't think he's in long enough. He took my daughters life, so why should he come out and have his life," said Gaynor.

"I never thought I'd lose my daughter through domestic violence and I don't expect anyone else to as a mother... because the pain, it lives with you forever."

The parole board said decisions on prisoners being released were focused on what risk they could represent to the public and whether that risk was "manageable" in the community.

"A panel will carefully examine a huge range of evidence, including details of the original crime, and any evidence of behaviour change, as well as explore the harm done and impact the crime has had on the victims," it added.