Rose West became one of the most sadistic, sexually-motivated and depraved serial killers Britain had ever witnessed.
The twisted mother tortured and murdered at least 10 young women along with evil husband Fred West, including her own daughter, before eventually being locked up for life in 1995 while still maintaining her innocence to this day.
Despite what has been widely reported in the past, many experts and witnesses believe Rose actually had the dominant role in killing the defenceless victims - having murdered Fred's eight-year-old step daughter Charmaine when she was 17.
But how did Rose turn from a reclusive and disengaged child into a vicious killer?
New documentary Rose: Making of a Monster, which airs tonight on Channel 5, explores whether Rose was born evil or a product of her horrific upbringing.
One expert believes her killer psychology began in the womb before she was even born due to the brutal electroconvulsive therapy her mother received, while others point to her denial over being sexually abused by her father.
Controversial therapy before birth
Rosemary Letts was born in November 1963 - the fifth of seven children in a poor family.
Before she was born, her father Bill Letts was in the navy and was often away from home for months on end, leaving mother Daisy to look after the children alone.
During her pregnancy with West, Daisy suffered from severe pre-natal depression so Bill had to quit the navy so he could support his wife.
However, "brutal and violent" Letts struggled with the domestic duties when settling into civilian life as he "intimidated and terrified" the mother of his children.
Former neighbour Gill Job, who grew up next to Letts family, says she could hear "awful" screams, shouts and banging.
Daisy sank into deeper depression because of husband's terror, which was so severe she was given an electroconvulsive therapy (ECT) course.
The controversial procedure, which involved electrodes being attached to the skull, made patients have violent seizures.
Daisy had her last course of ECT just one day before Rose was born - and criminal psychologist Dr David Holmes says it would have impacted her brain development.
"In my view it could very well be argued that Rose's neurological development will have been retarded," explains Dr Holmes.
"To have ECT late in the gustative period. This is often the more sophisticated parts of the brain development. Inhibitory parts that give us a conscience, empathy, that stop us from doing heinous acts."
While her former solicitor Leo Goatley, who represented West in her 1995 trial, believes her killer psychology may have started before she was born.
He says: "I think where the mother is mentally ill, not engaging and stressed, suffering from anxiety, it’s all that stuff which impacts on the unborn child. The psychology starts in the womb."
As a baby Rose would rock her head, which Dr Holmes says is behaviour often seen in children who are abused as they get a comfort from the movement.
Father's sexual abuse
Daisy and Bill Letts continued having more children after Rose, but as the family grew so did the father's resentment towards them.
The Letts were described as a "dysfunctional family" that didn't fit into the community and the children were never allowed to play out.
Having lost his status and self worth, fire and intimidating Letts tried to regain his power at home by being regimented with the kids.
Geoffrey Wansell, Official Biographer of Frederick West, says Letts was a "tyrant of a father" who made his children clean the carpet with toothbrushes.
"Letts was a monster. From a very early age Rose would have seen the older children's fears," explains Wansell. "She had a childhood where she retracted from the world and went into a bubble of her own.
He adds: "There's no doubt Bill Letts altered his daughter considerably."
Letts was hiding a secret diagnosis that would cause his paranoia to intensify and he had severe psychotic episodes.
He was diagnosed as paranoid schizophrenic as teenager but never disclosed this to his family and didn't get treatment.
In fear of violence from Bill, Daisy developed an obsession with cleaning which became so intense the children weren’t allowed out in case they got dirty. he would do things like spoil the food and tip bins over.
Wansell says Letts "bullied, intimidated and terrified" his but was charming and friendly outside the home.
Amid an atmosphere of fear, Rose became reclusive and disengaged, so Letts would exploit her passive demeanour and abuse her vulnerable nature.
"When Bill inflicted sexual abuse on Rose he was limiting her development," says Dr Holmes.
"She was learning the wrong skills and the wrong motivations for life. She was on a path that would almost certainly to abusive relations in the future and be a instigator of abusive relations."
Even after Rose was married to Fred and owned her own home, her abusive father remained an ever present in her life.
Father and daughter continued their sexual relationship into adulthood - with Fred's blessing - while he lived on their road.
"There was still a sexual relationship between Rose and Bill. At one point he was living in a caravan at the bottom of Cromwell Street," says Wansell.
"I think Rose was always fascinated by her father. They couldn’t stay apart they were in a sense inextricably linked. You couldn’t break that."
Goatley, Rose's former solicitor, adds: "I've always found it extraordinary that Rose continued having sex with father into adulthood. Whether she got any sexual satisfaction from it I don’t know."
He says West has been unable to confront the reality of her childhood and described it to him as a "sugar sweet candy-coated flossy merry time".
Goatley adds: "She presents the home life as these vigilant overprotective parents who would do anything for their children which was complete nonsense."
School bullying
West struggled socially and academically and was slow to pick up on reading, writing and arithmetic.
At school, Rose was a self-absorbed recluse and was never allowed to play with other children.
When both her parents got jobs she was left in charge of her younger brother who Wansell says became her "play things".
She was held back a year but gained confidence being oldest kid in class and reached puberty before the other kids.
As Rose matured she went from being timid to a big strong girl who could "knock people about" and used violence to protect her brothers.
Dr Holmes explains: "Rose began to identify with Bill and thinking of herself as someone who was strong and could create fear in others. And this actually led to Rose going out and bullying other children."
Twisted relationships
Years of incest and abuse had normalised sex for West and earned her a reputation as a nymphomaniac among the local older men.
When Fred was 27-years-old he met Rose, who had just turned 15, at a bus stop and they got chatting.
While not initially attracted to the man who would become her husband, she said he could "charm the birds off the trees".
They discovered they had lots in common - mothers called Daisy, lived close by, and both had committed incest.
Dr Jane Carter Woodrow, author of ‘Rose West: The Making of a Monster’, says: "When Fred started to talk about things of a sexual nature to do with bondage, S&M, all the stuff he was into, any other girl would have run off but Rose stayed. It was quiet a normal thing she knew of."
Wansell adds: "I think Fred sensed in an almost animalistic way this is someone who can help me do what I want to do."
Having left his estranged wife Rina, Fred invited 16-year-old Rose to move in with his daughter and step daughter.
Weeks after they welcomed first child together, Rose was left alone to raise the kids when he was sentenced to 10 months in prison for theft.
First victim Charmaine
In the summer of 1979, West crossed the line from motherhood to murder.
Fred's step daughter Charmaine, whose mother was his first wife Rina, always stood up to Rose who couldn't cope and would lash out violently.
Dr Holmes says Rose resented Fred having “baggage” in the form of children from previous relationships and applied the same draconian rules her father had around the house.
While Goatley added: "I think Rose, with the stress and luggage that she was carrying and the anger that she had within her, she was capable of killing Charmaine."
Rose used to tie Charmaine up and whip her, so it's believed she killed the girl in a fit of rage.
Her body was hidden in the coal cellar and Fred buried her under the kitchen floor when he was released from prison.
When Rina came seeking out where her daughter had gone, she became a problem for Fred so he murdered her.
West strangled his ex-wife and buried her dismembered body in a field near his childhood home.
House of Horrors
The West then moved into 25 Cromwell Street, which was later dubbed the 'House of Horrors.
"Rose finally gets her own domain and she rules it with a rod of iron. She rules her own children even more fiercely than Bill intimidated her as a child," says Wansell.
To help pay the mortgage, they changed upstairs into bedsits and lent to young people, while Rose began working as a prostitute in one of the spare rooms.
Fred peered on her through spy holes and had an intercom system to listen - taking pleasure in having sex with Rose after she had sex with other men.
Dr Holmes says: "It gave them the chance, as it were, to partition their lives to be able to control element, for Fred to engage in voyeurism activity with Rose’s sex activity."
They pushed boundaries and experimented with fetishes and eventually converted the basement of their house into a torture chamber.
Murdering young women
Fred and Rose would drive around looking for young female victims.
They murdered their own 16-year-old daughter, Heather West, in 1987 having sexually abused her throughout her life.
Other victims included Alison Chambers, 16, Shirley Robinson, 18, Juanita Mott, 18, Shirley Hubbard, 15, Theresa Siegnethaler, 21, Lucy Partington, 21, Carol Ann Cooper, 15, Lynda Gough, 19, and Anne McFall, 18.
Fred was accused of sexually abusing his 13-year-old daughter Mae in 1992, which launched a child services investigation into the disappearance of Heather and five of the West children were taken into care.
They claimed Fred often joked Heather was buried under patio, so the police got a warrant to search the house in 1984.
Fred confessed to killing Heather and her body and other human remains were found under the Wests' house, which led to their arrest.
After Fred confessed to the killings, he led police to more bodies under cellar.
Imprisoned for life
Despite Fred claiming all responsibility and confessing where victims were buried, police had enough evidence to arrest Rose on suspicion of murder.
Rose was charged with 10 counts of murder but didn't show any emotion in court and didn't even look at her husband.
"The clear instructions were she said she was innocent. If anything had happened it was because of Fred," says Goatley.
"They probably did discuss the fact that Fred would take the blame and she would walk away from it. she disowned him in the witness box.
"There were clear signs she was saying you’ve admitted it now go and rot."
Fred killed himself on New Year's Eve 1995 and was found hanging in his cell.
Rose faced trial alone in October 1995 and it soon became apparent that Fred had not been operating alone as the horrifying truth emerged.
John Hawkins, from Gloucester News agency, says: "She didn't appear to be upset or disturbed. I think it's possible she never really appreciated the enormity of what was going on."
After seven weeks of evidence and almost 100 statements from witnesses she was found found guilty on all counts of murder.
"When Rose was taken down she was totally distraught. The ground from under her feet disappeared and she was sobbing uncontrollably," says Goatley.
West maintains her innocence to this day but is currently serving a life sentence and will die in prison.
*Rose: Making of a Monster airs tonight at 9pm on Channel 5
