In the late 1970s, northern England was gripped by panic.
A serial killer stalked the streets of West Yorkshire and Greater Manchester, assaulting and killing women in savage attacks committed in public spaces.
"The night became something where there was danger," Tracy Powell, a journalist-turned-university lecturer who grew up in a nearby town at the time of the killings, told the Independent.
Dubbed by the British press as the "Yorkshire Ripper", his reign of terror began on October 30, 1975 with the murder of Wilma McCann in Leeds.
The mother of four was hit on the head with a hammer and stabbed several times in a football field 90 metres from her house.
She was discovered by a milkman making the early rounds the next morning.
Three months later, Emily Jackson was found dead with multiple stab wounds in a factory field in the same city.
More deaths followed in quick succession, and as the list of victims grew, so did a pervasive feeling that women were no longer safe walking on British streets.
The bogeyman that lurked in the dark was a man named Peter Sutcliffe.
It took six years for police to catch him in a case criticised for its blunders, sexist language and missed leads.
Sutcliffe was questioned several times by officers during the period of the killings but, each time, he was released without charge.
Hoax letters and a fake recording also briefly led detectives in the wrong direction at a pivotal stage of the investigation, prompting a search for a man with an accent unlike the one belonging to Sutcliffe.
It was only by chance that the Yorkshire Ripper was finally located and arrested on January 2, 1981.
Sutcliffe surprised everyone by suddenly confessing to the murders once in custody.
"It was just a miracle they did not apprehend me earlier, they had all the facts," he told his trial.
One of Britain's worst serial killers stalks the night
Sutcliffe was born in Bingley in West Yorkshire, and worked a hodgepodge of odd jobs after leaving school at 15.
One of his roles was as a gravedigger, where he was said to have stolen rings from the hands of the dead before he was let go for poor timekeeping.
He married his first girlfriend, trainee teacher Sonia Szurma, in 1974 and found work as a heavy-goods-vehicle driver.
His work took him all over the county, acquainting him with its secluded fields and quiet streets. Neighbours described him as reserved and softly spoken.
But at some point, he became obsessed with Bradford's red-light district and its sex workers.
In what is believed to be his first attack, Sutcliffe struck a sex worker in the back of the head with a stone after claiming she had run off with £5 before they had sex.
Police identified him as the attacker but no charge was brought because the woman did not want to pursue the case.
As time went on, his attacks escalated.
He would typically approach victims from behind, using a hammer to knock them unconscious before stabbing them with a knife or screwdriver.
Some of the women were found in empty fields or parks after being lured away from public areas.
Mothers and daughters were warned not to go out after sunset, messages that placed the onus of public safety on women's shoulders.
If they had to leave their homes, they were told to take a man with them.
The idea of an effective curfew outraged women in the area, who staged rallies and marched through the streets to protest violence against women and girls, and to demand that public spaces be safe and welcoming for all.
The press was quick to draw comparisons to another British serial killer, Jack the Ripper, who murdered five women in the east end of London in 1888 and was never caught.
But the reality was that the man at the centre of Britain's first true crime obsession was very different to the one who used northern England as his hunting ground.
Early theories and missed clues
Sutcliffe's reign of terror coincided with a difficult few years for Britain.
The industrial economy was in steep decline, ushering in a period of record strikes, political instability and social upheaval.
For those in northern England, there was also the disturbing possibility they might be a killer's next target.
Police initially believed the man they were after was targeting sex workers, after linking several victims to the trade.
Inquiries later chronicled how investigators missed key leads and ignored contradictory evidence by clinging to their initial theory.
One piece of vital evidence that may have been overlooked occurred early in the investigation.
In 1976, Marcella Claxton was returning home from a party in Chapeltown, Leeds, in the early hours when she met a man who mistook her for a sex worker and asked him for a lift.
"His eyes made him look a bit scary, but I got in [the car]. Quite soon I realised we weren't heading towards my home," she told ITV drama The Long Shadow.
When he pulled up at a park, she asked if she could go to the toilet, in the hopes of making an escape, but before she could get to the blocks, he hit her in the head with a hammer and drove off.
She survived the encounter and was able to help police produce a reconstructed picture of the man who attacked her.
She identified him as a 30-year-old, with black hair, a beard and a moustache.
Some detectives had a feeling the crime may be linked to the Ripper, but Claxton was ruled out as a victim because she was not a sex worker.
"If the police had listened to me, they could have caught him," Claxton told The Sun.
"There would have been no more killing … they asked me the same things over and over, but they didn't listen — they didn't believe me … if only they had listened to the description I gave, they might have caught him earlier and all those other poor women would not have died."
Detectives leading the investigation changed their working theory after 16-year-old Jayne MacDonald was killed in 1977.
It became clear that Sutcliffe was targeting any woman that was alone and that sex workers had become some of his targets because they would willingly get into his car.
Officers referred to MacDonald as the first "innocent" victim, language that was roundly criticised in later years for being sexist as it differentiated her from the other women who were killed.
John Robins, the chief constable of West Yorkshire police, has since apologised for the "language, tone and terminology used by senior officers at the time in relation to Peter Sutcliffe’s victims".
"Thankfully those attitudes are consigned to history and our approach today is wholly victim focused, putting them at the centre of everything we do," he said.
Over the course of the investigation, the squad assigned to the ripper case visited more than 23,000 homes, checked 150,000 cars and carried out more than 130,000 interviews.
Among them was Sutcliffe, who was interviewed — and released — nine times.
At one point, police even showed a picture of the killer's boot print near one of his victims, but failed to notice that Sutcliffe was wearing the exact same shoes.
Other missed clues in the Ripper investigation came down to the limited technology of the time.
A card index system was used in the Ripper incident room at Millgarth police station during the search, but it was overwhelmed by the flood of information coming in and was not compatible with other record systems, which meant evidence against Sutcliffe may have been lost in the system.
Police were also thwarted in their inquiries by hoax letters and a fake recording sent by someone claiming to be the killer.
A false lead
In early 1978, a letter arrived on the desk of Assistant Chief Constable George Oldfield, who was leading the hunt for the Yorkshire Ripper.
It was from a man who claimed to be the Ripper. A second letter was sent to the Daily Mirror newspaper.
"I am sorry I cannot give my name for obvious reasons I am the ripper," the first note said.
"…You and your mates havent a clue … Ive got things to do, My purpose to rid the streets of them sluts … Warn whores to keep of streets cause I feel it coming on again."
A third letter arrived a year later, as well as an envelope with a recording.
"I'm Jack. I see you are still having no luck catching me," the voice taunted in a 257-word message.
Officers began to suspect this was the person they were looking for and diverted resources to finding a man they wrongly concluded had a strong Wearside accent based on the tape.
But the messages turned out to be a hoax.
The man behind the fake calls and letters was discovered decades later.
John Humble, who was dubbed Wearside Jack, was charged and sentenced after a trial heard he had developed a "fascination" with the original Jack the Ripper.
The hoax communications gave the real killer time to kill more women.
By the end of 1980, 13 women were dead; and several others had been attacked by an unknown assailant wielding a knife, a hammer and a screwdriver.
Britain was in the grip of the biggest man hunt in the country's history, but while millions of police hours were expended on catching the killer, nobody knew where he was.
The hunt for the Yorkshire Ripper ends
In the end, the Yorkshire Ripper was caught by accident.
On January 2, 1981, two officers were performing a routine check in the red-light district of the South Yorkshire city of Sheffield, when they happened upon a car with a couple huddled inside.
When they ran the vehicle's licence plates in their computer system, they discovered they were fake and quietly arrested the driver. It was Peter Sutcliffe.
The next day police officers returned to the scene, and found the hammer that was used in most of the attacks hidden in a drainpipe.
The Ripper's crime spree came to a sudden end.
As police began their line of questioning, Sutcliffe surprised them all with a confession.
"It's all right, I know what you're leading up to. The Yorkshire Ripper. It's me. I killed all those women," he told detective inspector John Boyle.
He was convicted on May 22, 1981, at London's Central Criminal Court of 13 counts of murder, seven cases of attempted murder and was sentenced to 20 concurrent life terms.
Peter Sutcliffe spent the rest of his days in prison, where he died from COVID-19 complications in 2020.
Richard McCann, who was five when his mother, Wilma McCann was killed, told the BBC that "a lot of the families, surviving children of the victims, may well be glad he has gone and they have a right to feel like that".
"The attention he's had over the years, the continuous news stories that we've suffered over the years, there is some form of conclusion to that," he said.
Sutcliffe's reign of terror had an enduring impact on the residents who lived in the areas where he killed during the 1970s.
"[There was] fear in the homes of ordinary people," Ruth Bundey, a solicitor who lived in Chapeltown at the time and later went on to represent some of the Ripper's victims, told the 2019 documentary series The Yorkshire Ripper Files: A Very British Crime Story.
"Suspicion, looking at one's neighbours and thinking 'Could it be him?'
"Anybody who had a car dropping a woman home would wait until you had seen the woman get up to her front door, go in and put the light on. And you wouldn't go away until that had happened."
