The family and friends of murdered Hemsby woman Hannah Witheridge will tomorrow learn the verdicts in the trial of two men accused of killing her and a fellow back-packer on a picturesque Thai island. Investigations editor David Powles looks back on the case.

Eastern Daily Press: Koh TaoKoh Tao (Image: COPYRIGHT, 2006)

For many it's the time when loved ones flock home, ready to spend a magical few days surrounded by those closest to them.

But for the grieving families of Hannah Witheridge and David Miller, December 24, 2015 will be a date forever associated with something no parent, sister or brother should have to go through.

For, at around 6am British time, they will learn the verdicts into the trials of Zaw Lin and Wai Phyo (also known as Win Zaw Tun), the Burmese migrant workers accused of killing the pair and leaving their bodies dumped on a beach on the tiny island of Koh Tao.

The verdict, to be decided by a panel of three judges at the provincial court in Koh Samui, comes after 21 days of witness hearings which have not only put the spotlight on this tragic case, but the Thai justice system as a whole, amid accusations of shoddy investigation techniques, lost and incomplete evidence and even alleged brutality of the two accused in order to force a conviction.

Eastern Daily Press: David Miller and Hannah Witheridge are seen walking hand in hand around 1am as they leave an all-night party at Sairee Beach on the Thai island of Koh Tao. Picture: SUPPLIEDDavid Miller and Hannah Witheridge are seen walking hand in hand around 1am as they leave an all-night party at Sairee Beach on the Thai island of Koh Tao. Picture: SUPPLIED (Image: SUPPLIED)

Miss Witheridge's family will not be present in Thailand for the verdict, though Mr Miller's will be.

The bodies of the British backpackers were found on a beach on the island in the early hours of September 15, 2014. The murder weapon, a garden hoe, was found nearby. A post-mortem found that Miss Witheridge, 23, had died of head wounds and Mr Miller, 24, severe blows to the head and drowning.

Under intense pressure to find the killers, scores of Thai police officers were put on the case and in the days that followed Thailand was awash with rumours and theory.

On Friday, October 4, the country's national police chief, General Somyot Poompanmoung, announced that two men faced charges of murder, rape and theft. If found guilty, they could face the death penalty. But the pair continue to protest their innocence, as is shown in extracts from a letter, published today, sent to defence lawyers by the pair.

Eastern Daily Press: Hannah Witheridge murder trial. Pictured: Zaw Lin and Wai Phyo in prison bus. Picture: Sarah YuenHannah Witheridge murder trial. Pictured: Zaw Lin and Wai Phyo in prison bus. Picture: Sarah Yuen (Image: Sarah Yuen)

These are some of the key elements of the trial:

PROSECUTION CASE

A clear motive for the killings was not laid out by the prosecution and may never be known, whatever the verdict tomorrow. However, prosecution lawyers claim evidence points towards the Burmese migrants being responsible. This includes cigarette butts linking the men to the scene, where it is known they had been playing guitar, smoking and drinking on the night of the death.

THE CONFESSIONS

Central to the case has been the signed confessions by both 22-year-olds. This prompted bizarre scenes in the days that followed when they were made to re-enact what had allegedly happened, as a trail of people followed behind. The defence argues that if you watch back footage of this, the police are leading the man, rather than the other way around.

Within a few weeks the confessions were retracted amid claims the pair had been physically tortured and made to sign them by a police force desperate for an arrest while under pressure from Thai leaders.

The defendants are not native Thai speakers and it was alleged during the trial that on questioning, translation was carried out by Burmese pancake sellers with a poor grasp of Thai and that a confession made on camera differed from the translated testimony. The defence claim the prosecution was unlawful.

THE MOBILE PHONES

A key element of the prosecution was the discovery of Mr Miller's mobile phone and sunglasses near to where Wai Phyo was staying. The accused claimed he had found it on the beach on the night of the murders and taken it home and that when they heard what had happened one of his friends smashed it up and threw it into some undergrowth.

THE DNA

The prosecution claims DNA from the accused matches that found on Miss Witheridge's body. This led to bizarre scenes in court when the defence asked for the DNA to be independently verified but were initially told there was nothing left to retest. There were then reports the evidence had been 'lost', which national police chief Gen Poompanmoung claimed was a misunderstanding.

The defence reversed then its demands for the DNA to be retested because they felt it could no longer be verified as reliable and called for the court to regard it as inadmissible as evidence. No DNA of the accused was found on the murder weapon. In fact a forensic expert said she had extracted samples of DNA from the alleged weapon and they matched two different males.

The defence also claims Mr Miller's mobile phone and sunglasses were not tested or analysed to accepted international standards and there was a raft of missing evidence in the case, including photographs of the crime scene, autopsy and some DNA analysis.

THE 'RUNNING MAN'

CCTV footage of the so-called 'running man' was shown in the trial and the prosecution claimed it was Wai Phyo leaving the scene in a hurry. However, defence lawyers sent the footage for 'gait analysis' by experts at Acume Forensic, in the UK, who said the footage 'lends no support' to the claims it was one of the accused.

The defence have also criticised the failure of the prosecution to present any other CCTV footage from the night.

MYSTERIOUS BLONDE HAIR

A single blonde hair was found in Hannah's hand. It does not matched either of the victims or accused.

Visit our website tomorrow for the verdict in the trial and to see the letter from the accused in full.

Did you know Miss Witheridge and want to pay tribute? Email david.powles@archant.co.uk

THE VICTIMS

'Beautiful...intelligent...loving...selfless...caring...bright...witty.'

These were just some of the many words of tribute paid to Hannah Victoria Witheridge, (pictured) by her many family and friends in Norfolk and beyond in the days and weeks after the tragedy.

The 23-year-old grew up in Hemsby, where her family run a handful of holiday parks. Growing up she developed a love of horse-riding, performance arts and music. She attended Langley School and City College Norwich before gaining a BA in education studies at the UEA in 2012. After that she worked for a short while as a sales administrator at Archant's head office in Norwich, prior to moving to Colchester to study speech therapy at the University of Essex.

In their first statement following her death, her family said: 'Hannah was a beautiful, intelligent, loving young woman who poured joy into the lives of all who knew her. She was selfless and caring and made each and every day that little bit more wonderful.' Her funeral, held at St Mary's Church, in Hemsby, just five days before what would have been her 24th birthday, was attended by hundreds of people, dressed in colourful clothes at the request of her family. Miss Witheridge and David Miller (pictured below) were not travelling together and had met on the island. The 24-year-old, from Jersey, was travelling with a friend after finishing a degree at Leeds University.

THE CASE WILL GO ON

No matter what the outcome of tomorrow's hearing, the case is unlikely to be over for some while yet.

It is understood both defence and prosecution are likely to launch an immediate appeal depending on the verdict, dragging out the ordeal for family and friends of both victims.

The Thai courts have two stages of appeal, the first the Court of Appeal, which can either be heard at the main court in Bangkok or several regional courts. The second and final stage is The Supreme Court, where cases can sometimes take years to be completed. Thailand doesn't operate a jury system, instead having Judges and Presidents presiding over cases.

QUESTIONS OVER INVESTIGATION

As attention fixed on Koh Tao in the days after the murder, Thai investigators and authorities appeared ill-equipped to cope. Even if Christmas Eve brings a guilty verdict, Thai police in particular are likely to face questions from their own media about their handling of the case. Some of those concerns included fears the murder scene had not been properly secured, potentially crucial evidence being lost and the police, early on in the investigation, appearing to lurch from one theory to the next.

The bizarre sight of the accused being made to re-enact the alleged murders in front of dozens of onlookers did little to appease those worries.