Dreda Say Mitchell: The star schoolgirl athlete who lept over higher hurdles to succeed in crime fiction

Dreda Say Mitchell was born in London to Grenadian parents in 1965. She grew up on an estate in the East End and went to a Catholic girls' school. After a degree in African history at the School of Oriental and African Studies, London, she trained as a teacher. She has taught in schools throughout the East End and is now an education adviser, specialising in literacy programmes for underachieving black boys. Her first novel, Running Hot (Maia Press, 2004), won the Crime Writers' Association's award for best first novel. Killer Tune (Hodder & Stoughton, £11.99) was published last week. A judge of the 2007 Freedom of Expression Awards and the CWA's New Blood Dagger awards, Mitchell is working on a new novel, Geyser Girls.

When Dreda Say Mitchell announced that she was giving up athletics, there was a stunned silence. Everyone thought that the young girl who had demonstrated outstanding prowess on every corner of the playing field, the current east London shot-put champion, could only go on to greater athletic glory. "Some of the children started to laugh," says Mitchell, almost wincing at the memory, "and I blushed. I wondered," she continues, "if this was happening in society, that as black youth we were being channelled into particular things. I just decided that I wasn't going to do the sports any more. I was going to do the academic studies instead."

The daughter of a Grenadian father who left school at 13 to become a fisherman, and who later worked in a chicken factory in Bethnal Green, and a Grenadian mother who worked as a "domestic" in Mile End hospital, she grew up in a home with no books, but a deep respect for learning. "My mum would drag all four of us and the neighbours' kids to the library," she remembers, "which happened to be Whitechapel library. It was just the most amazing place. We used to sneak into the art gallery at the same time. I get quite upset," she adds, "at people's depictions of housing estates, all this sense of deprivation, these poor, poor people. Quality of life goes beyond money."

Whitechapel library, which inspired so many working-class autodidacts, no longer exists. Instead, there's a gleaming, glass-plated "Idea Store", a multi-million-pound mecca to modernity nestling behind the sari and fruit stalls on Whitechapel High Street. No doubt somewhere among its banks of computers there's still a crime section, in which you can tuck into a nice murder, as if it was something that happened only in the sanctuary of fiction. And if the librarians are doing their job, then prominent among the new acquisitions will be a book with a striking black-and-white jacket, bearing the giant words "Killer Tune" and underneath, in blood red, the name "Dreda Say Mitchell". Yes: local girl hits the big time. And does it by writing about the streets where she grew up.

As a child, Mitchell never thought she would become a writer, but always loved telling stories. "I never saw my dad read anything other than the News of the World or the Sun," she says, "and I never saw my mum read a book, apart from a hymn book - to sing along to Songs of Praise - or the Bible. But in our house there was this tradition of stories. My dad used to have these friends come round on a Friday and they'd play dominoes or drafts and they were always telling stories... When I think of the drama they would put into their voices, I think that's where I got my love of stories."

It was, as so often, an inspirational teacher who first encouraged her to commit that storytelling impulse to the page. "My history teacher used to bring the past alive," she explains, "and she'd get us to do these empathetic stories. Can you imagine if you were a child in Nazi Germany, or in the Blitz?" It was she who encouraged the insatiably curious teenager to continue history studies beyond A level, but it was a moment in the school library which set the path. "I looked up," says Mitchell, "and saw a book with a picture of a black person, and took it off the shelf. It was CLR James's The Black Jacobins", about the revolution in 1790s Haiti. "I was stunned. I thought, hang on, I've heard about the American Revolution, the French Revolution, I've even heard about the American civil war, but I've never heard about this revolution in the Caribbean." At that moment she decided that she was going to study not just history, but African history. She did a degree at the University of London's School of Oriental and African Studies and then trained as a teacher.

With the single-mindedness that marked her quiet announcement to her PE teacher, Mitchell ended up as a head teacher of a primary school in the East End – a job which she adored. After a while, however, she realised that "something" was calling her back. "I started to think back to when I was a child," she confides, "going to the library, and something else I've always wanted to do, which was write."

She signed up to an evening class in creative writing at Goldsmith's College and discovered "Schoolboy", the young man who was later to become the central character in her first novel, Running Hot. Based on "lots of different people" on the estate where she grew up, he is, says Mitchell, "everyday urban man, standing on a street corner, doing something he shouldn't". With the help of techniques she was learning in her classes, he began to take shape.

It was at a second course, at the Groucho Club, that those fragments began to turn into a novel. "I mentioned the course to a friend," she says, "and he said 'don't do it, you'll never get in'. He was working-class like me," she explains, "and it was a sense of 'we don't want to disappoint you'. But I've always had these high expectations of myself. It's like my parents coming over to England. If you don't try it, you don't know." Mitchell rang the tutor, writer and publisher Maggie Hamand, and was told there was one place left. "If I hadn't gone through that door," she grins, "I wouldn't be sitting here with you now."

"Here" is a pub in Stoke Newington, an area which features in both her novels. Running Hot, the novel published by Maggie Hamand and Jane Havell's independent press, Maia, is set in the streets of Hackney and surrounding areas, where "treading on someone's footwear could mean being permanently taken out of this life" and in which Elijah "Schoolboy" Campbell "always" takes "an interest in the death of former classmates". It's a world where "one minute you could be in school and the next having life press so hard you ease the pressure by forcing a gun into someone's face". A world, in fact, which seems a million miles away from the rough pub-turned-gastropub where we're sharing a charcuterie plate and sipping Chilean merlot.

Yet Hackney's "murder mile" is just down the road and yellow police signs requesting information on the latest "violent incident" spring up almost with the profusion of Wordsworth's daffodils. Like Hackney itself, which boasts bijou boutiques alongside its crack houses-cum-brothels, Running Hot offers a cacophony of voices across the classes. Pacy, vivid and at times extremely funny, the novel won the Crime Writers' Association John Creasey Award for a first novel. Mitchell became a regular fixture on literary panels and on Radio 4's Front Row. She also acquired an agent and a larger publisher.

The result is the brilliant Killer Tune (Hodder & Stoughton, £11.99). Set again in Hackney and the East End, it tells the tale of rap artist Lord Tribulation's discovery, following the mysterious death of his musician father, of disturbing secrets from the past, in which the violence of the 1976 Notting Hill carnival features heavily. It's a black Bildungsroman for the 21st-century, one which features a soundtrack woven together from the music of the past and present, and asks some searching questions about history and culture.

Lord Tribulation discovers that some of the names he uses as stage-props – Castro, Emmett Till, Huey Newton, Che Guevara – are not just words with brand recognition, but significant figures in a history of which he is largely ignorant. He does some serious learning and some serious growing up: a process painful for him, but a gripping roller-coaster for the reader.

"I wanted to explore the changing generations," she explains, "and the changing London." She was at the 1976 carnival and, aged 10, witnessed the sudden outbreak of violence. "For the first time, I was seeing black British people, black Londoners who were trying to assert their right to be black members of this society, to not be seen as people from the Caribbean. Caribbean communities," she continues, "are changing. People are dying and lots of people, like my dad, are going back. And I wonder if we're losing something here as well. The family network's beginning to fall apart and..." Mitchell tails off.

"Hang on," she says, "I think that's my cousin!" We wander over and I am introduced. "Have you read her book?" I ask cousin Colvin, who's settling down to a quiet pint with friends. He flashes me a long, lazy smile. "Of course!" he says.