Sometimes, in the three years that I spent researching the murders at 10 Rillington Place, I wondered why I had chosen to immerse myself in such dark material. John Reginald Halliday Christie, an apparently respectable middle-aged office worker, was charged with murder in 1953, when the remains of six women were found in his dingy flat in Notting Hill, west London. He had strangled and raped his victims, then hidden their bodies under the floorboards in his front room, beneath the flowerbeds in his tiny garden and inside his kitchen wall. I had written two accounts of murder before (The Suspicions of Mr Whicher, about an infanticide, and The Wicked Boy, about a matricide), but this was the first time I had studied a serial killer, or a crime in living memory.

I knew that I was not alone in being drawn to such stories. True crime documentaries and podcasts have soared in popularity in the past few years, and women are twice as likely as men to watch and listen to them. Increasingly, women have been telling these stories, too: Sarah Koenig and Julie Snyder made the podcast Serial, which has been downloaded more than 340m times; Laura Ricciardi and Moira Demos produced and directed the award-winning Netflix show Making a Murderer; and authors such as Helen Garner, Becky Cooper, Hallie Rubenhold and Michelle McNamara have published acclaimed books about murder.

In the New York Review of Books, Caroline Fraser argues that women have transformed the true crime brand, replacing the pulpy, lascivious reports of the mid 20th century with works of “retributive justice, recording and correcting the history of sexual violence”. A genre that was “once driven by male avidity”, she writes, is now “shaped by female anxiety”. In the Los Angeles Times, the crime novelist Megan Abbott suggests that women turn to these tales because they unearth “the dark, messy stuff” of their lives: “domestic abuse, serial predation, sexual assault, troubled family lives, conflicted feelings about motherhood, the weight of trauma”, all “the taboo topics the culture as a whole represses”.

A true crime narrative can be strangely comforting. Usually, it is shaped like a detective novel: it starts with a body and proceeds to dismantle the crime, establishing times and dates, names and ages, postmortem findings, the topography of streets and rooms. Where a thriller or horror movie builds up tension, the crime story steadily undoes an act of violence, restoring motive, logic and chronology to a scene of chaos. With this framing, the storyteller and the audience are cast not as weird people who are transfixed by suffering, but as good people who are seeking truth and justice. Such stories animate our anxieties, but they also soothe them. The killer and the victim are others, not us; the crime was there, not here; then, not now. On TikTok, young women post videos of themselves listening to true crime podcasts as they fall asleep.

I could trace the origins of my book to the summer of 2020, when the sisters Bibaa Henry and Nicole Smallman were murdered in a park in north London, and their assailant, Danyal Hussein, told the police that he had intended to murder six women in six months. I had always taken it as a fact of life that some men chose to kill women, but I now started to ask myself why. The next spring, when the Metropolitan police officer Wayne Couzens abducted, raped and strangled Sarah Everard, I looked for a story from the past that might help me understand. I dimly remembered the murders at Rillington Place – I must have watched the film about them some time in my teens – and when I looked up the details I learned that Reg Christie, like Couzens, had been serving as a policeman when he started to kill. And, like Hussein, he had been on a mission: he planned to murder 10 women.

I soon came across a long essay about the Rillington Place murders by Fryn Tennyson Jesse, a great-niece of the poet Alfred Tennyson, who had attended Christie’s trial and interviewed almost everyone connected to the case. Jesse was a pioneer of true crime writing. In the 1920s and 30s, while Agatha Christie and Dorothy L Sayers were producing ingenious mystery novels, she was publishing sharp analyses of real murders. Her first volume of essays was hailed by one reviewer as “a classic” that shed light on “the dark places of national life”. Other commentators expressed distaste for her morbid predilections. She had a “passion for grim, ugly, speciously passionate subjects”, complained the Observer. The Nation, more sympathetically, noted that she was “preoccupied with pain”. I became curious about Jesse, a woman who, like me, had delved into Christie’s crimes.

Jesse had led a troubled life. She described her mother as a cruel and capricious “fiend”, and her father, a clergyman, as a man whose sex life was “probably less well adjusted than anybody’s I have ever heard of”. When she was 24 she lost the fingers of her right hand to an aeroplane propeller, which left her feeling “most horribly mutilated”, and she developed a lifelong addiction to the morphine she was prescribed for the pain. After her marriage in 1918, she became desperately jealous of her husband’s mistress and his illegitimate son, and she was devastated by her own inability to have a baby. She more than once tried to take her own life. By reading and writing about murder, Jesse could escape into emotions – a killer’s fury, a victim’s terror – even stronger than her own. And she could revisit scenes of cruelty and perversion as a beady detective rather than a bewildered child.

Few women of Jesse’s generation were able to work directly on criminal investigations, but she, as a writer, could carry out her own inquiries. Like Agatha Christie’s Miss Marple, and like the dogged internet sleuths who star in documentaries such as Don’t F**k With Cats, The Keepers and I’ll Be Gone in the Dark, she was the plucky amateur who dared to challenge the official line. When Christie was arrested in March 1953, Jesse had just learned that she was going blind, but she was frantic to cover the case. Christie was “an excessively inquisitive creature”, she observed: he liked to spy on women, to photograph them, to keep their bodies near him. She learned that he had gassed his victims before raping and strangling them. She wrote: “He assaults his subjects in a defenceless condition, his sexual excitement is intensified by their helplessness.” Jesse was determined not to be helpless. She wanted to know her enemy – to look back at him.

By the time Jesse watched Christie’s trial at the Old Bailey in June, the Rillington Place story had become even more contentious. Three years before Christie was arrested, it emerged, he had appeared as the chief witness in the trial of his upstairs neighbour Timothy Evans, who had been charged with strangling his wife and one-year-old daughter, Geraldine, at 10 Rillington Place in 1949. There was strong evidence against Evans, chiefly a detailed confession he had made to the Notting Hill police, but in court he claimed that Christie was the killer. Evans’s accusation seemed absurd. He was found guilty, and in 1950 he was hanged. But now that Christie had been exposed as a killer, some suspected that he had framed Evans for murders that he had himself committed. If so, the English courts had overseen a shocking miscarriage of justice.

To work out which man had killed Beryl and Geraldine Evans, Jesse interviewed the pathologists, psychiatrists, detectives and barristers who had worked on both cases. She went to Notting Hill to visit 10 Rillington Place and to call on Evans’s mother and sisters. Eventually, she reached a conclusion about who had committed the double murder of 1949. Her essay, published in 1957, was not just a psychological study of a serial killer, but a whodunnit.

A true crime story, like a detective novel, can relieve our anxiety by locating badness in a single person, rather than in our society or ourselves. In the Irish Times, Fintan O’Toole proposes that his country’s obsession with the murder of Sophie Toscan du Plantier in West Cork in 1996 has served as “a giant deflector” from a deeper national malaise. By fixating on a mystery in which an Englishman is the chief suspect in the killing of a French woman, says O’Toole, the public is able to ignore the “vicious ordinariness” of the murders of Irish women by Irish men. The Du Plantier case, he writes, “allows us to pretend to be talking about violent misogyny when we are, in fact, avoiding that very subject”. In England in the 1950s, Jesse and others described Christie as an outlandish horror: a “psychopath”, a “monster”, a “creature”. But, 70 years on, it is easier to see him as a product of his place and time, a grotesque amplification of widespread prejudices, fantasies and fears.

In the newspaper reports of the Rillington Place murders, the victims were often presented as sexual objects. The tabloids described their “well-developed” and “scantily clad” bodies, as if inviting the reader to participate in Christie’s fantasies. I realised that to write about these women’s deaths at all was to risk replaying his peepshow. Perhaps even investigating their lives was an invasion of their privacy: they had not chosen to be part of this story. But to look away from these women might be to repeat Christie’s indifference to them, as well as the social indifference they had endured. The police files on the murders gave me glimpses of experiences rarely reported in contemporary books or newspapers.

Most of the young women Christie killed had come to London in search of freedom and independence. In a city worn down by years of war and austerity, they scraped a living in factories, pubs and cafes. Some traded sex for money or favours, posed for pornographic photographs and risked their lives in backstreet abortions. Ruth Fuerst, Christie’s first known victim, was a Jewish refugee from Austria who trained as a nurse before being interned in a camp on the Isle of Man. Kay Maloney, his fourth known victim, slept in a public lavatory on the Edgware Road and visited local pubs to drink Stingo, a treacly ale, and Jelly Jump-Up, a fortified red wine. Rita Nelson, his fifth known victim, wore a red skirt and a purple scarf to the Shepherd’s Bush cafe at which she worked, and clenched a cigarette between her teeth as she made sketches of the lorry drivers who came in for lunch. “I want to capture life as it really is,” she would say. All three women had young children whom they had been forced to surrender at birth.

Jesse was oddly incurious about Christie’s victims. They were “murderees”, in her phrase, “poor little tarts” whose lives had been bound to end in violence. I wondered whether she adopted this chilly hauteur in order to avoid being thought girlishly soft or sentimental, and to avoid thinking too much about what the women had suffered. Perhaps it was also a defence against fear: there were some women who were doomed to be victims, she implied, and others who would be safe.

To write about these murders, I, too, needed strategies to protect myself. The facts of the case were so disturbing, and so sad. I wondered if I might piece together the story by shadowing both Jesse and an ambitious tabloid reporter called Harry Procter who had covered the investigation as it unfolded. They might be my companions, I thought, taking me closer to the action while shielding me from it.

Most of the documents on the Evans and Christie cases were sealed when Jesse and Procter carried out their research in the 1950s, but thousands have since been opened to the public. As I combed through the vast dossier at the National Archives in Kew, I came across a prison memorandum that suggested a new solution to the mystery of who killed Beryl Evans and her baby. Then I found an exchange of letters that showed how the information in the memo had been concealed. It was irresistible, of course, to play detective myself.