The way the bright, happy teenager’s life was violently snubbed out shocked the country.
Fourteen-year-old Elsie Frost left her home in Wakefield on October 9, 1965, on to teach a group of children how to sail on a local lake.
But she never made it back home, and her body was discovered by a dog walker at the bottom of a flight of steps near a pedestrian tunnel, near a canal towpath.
She had been stabbed five times - twice in the back, twice in the head and once through her hand.
A trail of blood showed that she had been attacked in the middle of the short but dark tunnel but managed to stumble to the end, collapsing and dying of her injuries just minutes before she was found.
Elsie Frost murder: Family of girl, 14, win High Court bid to have fresh inquest
Elsie’s murder - and the huge police investigation to catch her killer - dominated the headlines.
Scotland Yard detectives were drafted in to help local forces in Yorkshire, thousands of people were interviewed, more than 1,2000 written statements were taken and 400 people who lived within a quarter of a mile of the murder were traced and their movements checked.
But the days turned into months, then years, and baffled police didn’t get any closer to solving the crime and there were no successful prosecutions.
Then, in 2016, more than 50 years later, police arrested a 78-year-old convicted child killer, Peter Pickering, on suspicion of her murder.
It gave hope fresh hope to Elsie’s brother and sister that they would finally find justice for their sibling.
But those hopes were dashed again last March after it emerged Pickering - who had murdered another 14-year-old girl in Yorkshire - died aged 80.
His death means he will never be charged.
However, a judge today ruled there would be a fresh inquest into Elsie’s murder, despite the death of the main suspect - which may finally at least allow her family to find closure.
Known as the ‘Beast of Wombwell’, Pickering had been had been detained under a hospital order since 1972 for the manslaughter of 14-year-old Shirley Boldy, who he admitted abducting, raping then killing in Barnsley.
And days before he died he was convicted of raping an 18-year-old woman, now in her 60s, weeks before Shirley's death.
Giving evidence, the woman, who cannot be named for legal reasons, described how Pickering took her to a secluded spot, handcuffed her, raped her, burned her breasts with cigarettes and told her she was going to be killed.
Detective Superintendent Nick Wallen, of West Yorkshire Police, said: "Peter Pickering was the man we arrested and interviewed over the last two years as part of the renewed investigation into the murder of 14-year-old schoolgirl Elsie Frost in Wakefield in 1965.
"We strongly suspected that Peter Pickering was responsible for her murder.
"We had been liaising with the Crown Prosecution Service and it was our expectation that Pickering would be charged in due course."
The news came as a hammer blow to Elsie’s family, who had campaigned tirelessly for her case to be reopened.
In 2016, on the 50th anniversary of her death, her brother Colin Frost and sister Anne Cleave made one last bid to get answers to the unsolved murder.
“We don’t want to die think we had not done anything,” said Colin, now 61.
“The ultimate, of course, is getting justice for Elsie in whatever shape or form it may be.”
He added that Elsie’s parents had died "with a huge amount of guilt" and without ever seeing justice.
The discovery of Elsie’s body in 1965 caused widespread shock and revulsion across the country.
As details emerged of the pretty, kind-hearted teenager, a hard-working pupil who had just been chosen as the next head girl at her school, the pressure on police to find the culprit grew.
Thomas Brown, who came across her body as he walked his dog with his young children, told the inquest: "When we got to within five or 10 yards of the bottom of the steps, I saw a girl lain there.
“She was lying with her left arm on the second step and her head was lying on her left arm and her right arm was above her head on the next step.
"She was crouched up in an awkward position with her legs underneath her body in a kneeling type of position but more on her left hand side.
"When I spoke to her I did not get any reply. I did not realise she was as badly injured as she was.”
The police were unable to establish any "apparent reason or motive for the attack" and did not know whether "she was the intended victim or merely passing at the time".
No one was traced "with the slightest animosity against the girl" and there was no evidence of a sexual assault and no sign of her having been robbed.
In January 1966, three months after the murder, a 33-year-old local man, Ian Spencer, a former railway fireman who was married with a son, was named by a coroner as the teenager’s killer.
Although he had been in the area of the murder on the same afternoon Elsie was killed, he insisted he was at home quite some time before she was killed.
Other witnesses, however, contradicted that story and claimed they thought they saw him close to the area where Elsie's body was found.
He was committed to face trial and spent eight weeks and two days in prison, but in March 1966 he was cleared due to lack of evidence and a judge instructed the jury to find him not guilty.
Elsie's family were left without answers until 2015, when police reopened the case and arrested Pickering, after finally uncovering “damning” and “compelling” evidence of Pickering being Elsie’s killer.
West Yorkshire Police discovered Pickering had two secret lock-ups in Sheffield and Liverpool, crammed full with suitcases.
Inside, officers had found handcuffs, women’s underwear, diaries, letters, paintings and exercise books filled with his vile rantings.
They also discovered the unposted letter dated October 1965, which he had written to a girlfriend, who lived minutes away from the Elsie Frost murder scene.
She had dumped him and he had ranted: “You have caused me to do what I’m about to do – you watch what happens next!”
“…I will surely go down in flames this time…I shall have to take someone with me when I go. So now what?
"To join the Devil…now I’m really going to get good and bloody nasty. Thanks to you.”
He finished by telling her she would probably next hear about him in the newspapers.
He had even painted a giant canvas while he was in hospital which appeared to be the steps down to the tunnel where Elsie’s body was discovered.
Police digging later uncovered proof he’d conspired with his mum to create a fake alibi for the day Elsie was set upon as she walked home.
Speaking about the reopened, three-year police investigation into Elsie’s murder, DS Nick Wallen said: “When we started we literally had nothing.
“No eye witnesses, no DNA and no exhibits at all to work with, the evidence had all been destroyed.
“It seemed like mission impossible.”
At the time of Elsie’s murder Pickering had been on the run for a vicious sex assault on a 14-year-old girl in the North East.
But it’s believed he returned to West Yorkshire, where he murdered Elsie.
As the evidence mounted police returned to Pickering for a final interview.
And when challenged about not being in France, he said: “Actually, you’re right. I’ve got it wrong. I was in Barnsley, not in France.”
DS Wallen said: “After that interview a member of staff at the hospital got in contact and told us she’d had a conversation where Pickering had re-enacted how he had stabbed Elsie.
“Pickering had told her: ‘Do you know how difficult it is to stab someone in the head? It’s hard to pierce the skull. I imagine they think I did this.’ He then mimed the murder, raising his arms above his head.
“It was chillingly accurate in terms of how the blows had been inflicted on Elsie,” DS Wallen said.
The 80-year-old was days away from being charged for Elsie's murder when he dropped dead of a heart attack in a psychiatric hospital.
DS Wallen said: “We were all gutted when he died. The evidence we had against him was damning. ”
Despite the blow, Elsie’s brother and sister said today they are “elated” that a new inquest has been ordered, and that they might finally find answers for their sister, after 54 years of uncertainty and disappointments.
Colin, who was six years old when Elsie died, said: "We've come a long way for this. We've fought and fought and fought.
"It just feels as if we've vindicated everything.
"I'm totally elated with what we are going to achieve for Elsie. We are going to leave a legacy after all of this."
