So there you are, a 16-year-old girl on your way home from a night out at the cinema. You live in Fontenay-sous-Bois, part of the Parisian banlieue, which means “suburbs” but also so much more, because these are the places that ring the city, where authorities have pushed immigrants, poverty and trouble. But you have avoided trouble so far.

You are a good student. You are pretty, slim, with long dark hair, and you are tomboyish, preferring tracksuits, preferring not to stand out, happy to do well at school then come home to your mother and younger brother. But on this particular evening you cross a group of young lads. They are smoking weed and drinking. You get too close; the leader grabs you round the neck and drags you into a nearby apartment block and orders you to “coucher” (sleep with them). You are a virgin and of course you say no, so he hits you hard in the face, then rapes you first vaginally, then anally, then forces you to give him head, right after the anal rape.

He is only the first. The rest of the group take their turn, patiently raping, despite your crying and vomiting. Somehow you get through it, but the next day they are waiting for you at the bottom of your block, and they do it again. They know where you live, they threaten to set fire to your flat, rape your mother, harm your brother. You believe them so when they tell you to come back the next day to be raped, you do. You couldn’t say how many rapists there were. Sometimes half a dozen, sometimes twenty-five, sometimes a line of boys waiting. Such patient rapists.

That is how it is every day for the next six months, and it continues despite your vomiting and passing out, in disgusting stairwells and empty garages. It continues though your mother asks you why you are showering up to ten times a day, but you daren’t tell her. Then during one session in a garage, another lad you know arrives and yells at all the rapists to leave, and they do, astonishingly, and the next day they don’t come back. Some still beat you when they see you but it’s not until one beats you unconscious that you are sent to hospital bleeding and finally tell the truth.

Except that's not the truth, according to French justice. Because that is the story of Nina, a young Parisian woman, who dared to take her rapists to trial in the Cours d’Assizes of Val de Marne, and who has just been told, along with her co-defendant, another young rape victim given the pseudonym “Stephanie”, that the French state believes the young men who say that she wanted it, that she was consenting, that they weren’t there.

How else to understand the sentences? Six acquittals. Four prison sentences, but three suspended. The severest penalty was one year in jail. Twelve months for six months of multiple, ferocious, sustained pack rape.

I prefer the term pack rape, because gang rapes do not always involve street gangs, but they always involve packs. The French have other names for it: the law talks of viols en réunion, which sounds too much like a picnic. Sometimes they are called viols collectifs. Or there is tournante, a word I discovered in 2003 via a film shot by a former high school teacher in his former high school in Sarcelles, that featured a tournante, or pass-round. You pass round (faire tourner) a joint; you pass round (faire tourner) a girl. They are both legitimate booty, if they have transgressed the viciously misogynistic codes that can arise when you take patriarchal religion, poverty and fury and mix them together. Feminists call this intersectionality: when gender and class and other issues intersect, and women are damaged by the consequences. I call it horrific.

Back in 2003, I interviewed girls who told me that they couldn’t wear a skirt to school because that meant you were a slag. They knew of a girl who had worn one anyway and been attacked by 30 boys in the school toilets. They couldn’t wear lipstick. If they fell in love, their boyfriends generously shared them amongst their friends. A helpful police officer in one northern Parisian suburb showed me police dossiers of a dizzying darkness. I watch a video deposition of Elodie, 14, who answered the door one evening and five minutes later had been shoved into her dining room and had the first of five penises in her mouth. When she gives her testimony, her hands never leave her face. Solange, 17, whose boyfriend held her while his friends raped her. When she dumped him, her next boyfriend did the same. One girl I read about was raped 86 times. I wonder now if that was Nina.

Then Samira Bellil wrote a book called Dans L’Enfer des Tournantes (In the Hell of Tournantes). Samira was a pretty girl with corkscrew curls and cornflower blue eyes, of north African background, who fell in love at 14 with a man who soon delivered her to three of his mates, then again and again. Like Nina, Samira went off the rails, into foster homes, drugs and delinquency. And like Nina, she found the extraordinary courage to denounce her rapists, then to write a book and put her face on the cover, “because my publisher says I have a pretty face”.

Samira died of stomach cancer in 2004 – brutalised internally, I am sure – at the age of 31 but the feisty organization Ni Putes ni Soumises (Neither Sluts nor Doormats) that she helped found is still going, and still angry. They are still needed. When I asked French feminists in 2003 why they weren’t screaming about tournantes, Julia Kristeva sent me an old paper she had written about “the damage to psychic space”. Are things better now? The contemptuous verdicts in Nina’s trial have got widespread attention. Ministers have commented. The legal teams of Nina and her co-defendant ‘Stephanie’ called the verdict “a judicial shipwreck”, whatever that means. But the case took 13 years to get to trial. In all that time, Nina was given little financial or psychological help. She was moved away from her rapists, but the hostels, pillars and posts made her desperate enough to move back home to live with her mother.

But her mother still lives in Fontenay-sous-Bois, and her rapists still live there too. That is where she probably went after that verdict, to the apartment blocks and garages where she was raped, where her rapists still hang out, where an outraged comment from a minister is no defence.

She was brutalised by her rapists, and then French justice assaulted her some more.

Rose George is a journalist and writer. She tweets @rosegeorge3