Image copyright Drinkwater family photo Image caption Muriel (centre) was attacked as she made her way home from school in 1946

A schoolgirl's murder has gone unsolved since she was brutally killed more than 70 years ago. Police had been hopeful forensic evidence - thought to be among the oldest such specimens in the world - may finally prove who killed her. But the mystery still remains.

Twelve-year-old Muriel Drinkwater was singing as she walked along the mile-long path to her home after getting off a school bus.

Her mother Margaret watched from the house as the youngest of her four daughters went among the trees and disappeared from sight.

It was the last time her mother saw her alive.

The next day the child's body was found. Muriel had been brutally raped, battered around the head and shot twice, with her killing dubbed the Little Red Riding Hood murder by the national press.

Thousands of men were questioned over the shocking death of Muriel, a schoolgirl at Penllergaer Grammar School on the outskirts of Swansea.

Posters featuring the weapon used and a description of a man wanted for questioning were circulated widely but yielded no results.

Image copyright Mirrorpix Image caption The handle of the murder weapon used to kill Muriel had been modified with Perspex

Despite the effort and resources ploughed into finding the killer, the inquiry remained unsolved.

It had been hoped a vital piece of forensic evidence might finally lead police to the identity of Muriel's killer.

A semen stain found on her coat is thought to be one of the oldest pieces of crime scene evidence in the world.

It was discovered during a 2003 case review, and was used to rule out a boy who passed Muriel before she was attacked as a suspect.

Image caption Harold Jones was given a gold pocket watch to celebrate his original acquittal for the murder of Freda Burnell

South Wales Police were looking into whether Harold Jones, who murdered two young girls in a town about 45 miles away, also killed Muriel.

But after re-examining the forensic evidence and considering theories that Jones was responsible, they have confirmed he was not the killer.

Detective Chief Inspector Mark Lewis, head of the South Wales Police's Specialist Crime Review Unit said: "The results of the forensic examination categorically confirm that Jones was not responsible for the murder of Muriel Drinkwater.

"Due to advances in forensic technology, we have been able to look again at evidence from the murder in 1946 and I am now able to rule out Harold Jones completely as a suspect in this case.

Media playback is unsupported on your device Media caption Who killed "Little Red Riding Hood"?

"I have spoken to Muriel's family to bring them up to date with the latest details of this investigation."

The news will be a blow to historian Neil Milkins, who has spent 12 years researching Muriel's murder and took his theory to the police.

Speaking before the results of the DNA sample were known, he said: "Harold was a convicted double child murderer - suspected of being one of Britain's most notorious serial killers.

"He would have had no problem committing this murder."

Growing up in Abertillery in a poor family, Jones left school in his early teens and began work as a shop assistant.

But in February 1921, aged just 15, he lured eight-year-old Freda Burnell to a seed store behind the shop and killed her in a vicious attack.

He hid her body and dumped it in an alley during the night.

As the last person to see her alive, Jones was arrested and put on trial at Monmouth Assizes.

Image caption Freda Burnell and her friend Florrie Little were killed by Harold Jones in their hometown of Abertillery

But local people believed he was "fitted up" by the London detectives and campaigned for his release.

After being found not guilty and released, he was paraded through the town shoulder high by his supporters and presented with a gold watch.

Yet within days of his acquittal, he struck again.

This time it was Freda's friend, 11-year old Florence Little.

He lured her to his home, slit her throat, then hid her body in the attic.

Upon the discovery of her remains, Jones admitted both murders and was jailed for 20 years.

When he was released in 1941, he joined the army, serving in Libya before his military service ended in February 1946.

Muriel was murdered four months after he left the forces, leading Mr Milkins to suspect it may be him.

Mr Milkins said: "Just before he was released from prison, he told authorities he didn't want to lose the desire to kill and rape.

"So it seems to me, and also psychologists, he may have gone on to kill many more times.

"He was a psychopath, so calm and cool.

"It seemed he could kill someone, walk away, and talk to people with no nerves at all."

There is a school of thought that Jones was also Jack the Stripper, a notorious killer who strangled six women in London in the 1960s.

Jones lived in the area at the time of the killings, and a 2018 investigation led by criminologist Prof David Wilson, named him as the prime suspect.

Jones later went on to have a daughter, who knew nothing of his crimes, and he led an "unassuming life" until his death from cancer in 1971.

Image caption Jones was released from prison in 1941

As for the unsolved murder of Muriel, the re-opening of the cold case involved examining very old DNA was something that was highly unusual, according to one expert.

Speaking before the DNA results were known, Dr Jane Monckton Smith, a forensic criminologist who grew up near Muriel's home town, said: "Personally, I don't know anyone using a sample so old.

"It's amazing that we have come so far that we can extract a profile from it.

"From what I know, Harold Jones was a sexual sadist and from my limited knowledge, I think it's highly likely he is a good suspect in a number of murders."

For Muriel's niece, Margaret, she is back at square one, still waiting for an answer to who killer Muriel.

She said: "Muriel was my aunt, and my mum and her had a very happy childhood on the farm.

"The murder of her little sister had a massive effect on my mother and family.

"Ideally, I would like to put it to rest, because it's an open case.

"We still need justice for Muriel."