AS LIN ANDERSON AND I DISCUSS true crime and crime fiction, she fishes a newspaper out of her bag and holds it up. The front page shows the conclusion of the Sheffield incest case: "Rape father jailed over daughters' nine children." Her point: no matter how dark your imagination, you can't top real life.
Anderson's novels, featuring Glasgow-based forensic pathologist Rhona MacLeod, go to some very dark places, from internet paedophilia to ritual murder. Her fifth book, Easy Kill, deals with a serial killer targeting prostitutes in Glasgow and burying them in shallow graves in the city's Necropolis. Still, she maintains that true crime is even more grim. "Whatever we make up in books, the truth is that it never matches reality. When I did a forensic science course, that became really obvious. The truth of what these people face every day – you couldn't make it up."
Anderson, 58, a former maths teacher turned rising star of tartan noir, signed to publishing giant Hodder two years ago. She has made her way in the world of books with a level head and a sunny disposition. "I didn't see myself as a computing teacher at 60," she says brightly. "But I don't think there's a problem with being a writer."
Well before CSI became a must-see on primetime television, she was inspired to make her lead character a forensic pathologist by a former pupil, who now works with the Metropolitan Police in London.
"Emma would come back and talk about her work. It was that wonderful mixture of the horror and the humour, the way they survived. I had an idea for my first novel about someone turning up at the scene of a crime and finding that the victim had something to do with them."
Aware that she knew nothing about forensic science, Anderson took the forensics course at Glasgow University. "It's the best thing I ever did," she says. "It's been endlessly fascinating."
Anderson's feisty female protagonist – she didn't want another detective with a drink problem – has been described as "a sexy new rival for old Rebus", though she is quick to point out that Ian Rankin is both a neighbour and a friend. Her books combine elements of thriller and detective story, cold hard facts and a warm sense of empathy with her characters. Over five books, she has established a close-knit gang: Rhona and her on-off musician boyfriend, Sean; her garrulous assistant Chrissy; family man DI Bill Wilson, and his sidekick, the womanising McNab.
If Rhona gets herself into more immediate danger than most forensic scientists, this is balanced by the fact that the crime is often resolved through basic, routine policing, and the loose ends are not always tidied up. "You make it more exciting than it is because everything has to happen faster, but the truth is there," she says.
Anderson draws on her contacts among Glasgow's forensics experts – to source a specific type of seaweed found on a body (Fucus ceranoides gets its 15 minutes of fame in Easy Kill), or a particular plant or parasitical infection. Forensic scientists enjoy her books for their faithfulness to the profession.
Research will often help determine the direction of a book, as do real-life crimes. Anderson's last novel, Dark Flight, was partly sparked by the case of a child's torso found in the river Thames in 2001. Named "Adam" by police, his identity was never discovered, though he is believed to have been smuggled to this country from Nigeria and to have been a ritual murder victim. Likewise, the serial killer in Easy Kill may be fictional, but Glasgow is littered with the unsolved murders of young women working as prostitutes.
Anderson speaks with genuine anger about the attitudes that surround these cases. "It really upset me how these women were dismissed with such ease. They're not a daughter or a mother or a person, they were just described as 'prostitutes', as if they were disposable people." The emotional heart of Easy Kill is a middle-class mother hoping to save her drug-addicted daughter.
The fabric of the city of Glasgow is real too. The territory of Easy Kill cuts a swathe through the East End, from the Necropolis down across Duke Street and the disused railway yards off High Street to the red light district in Calton. The Molendinar Burn, which runs through this area in underground tunnels and caverns, came to play a key part in the story.
"I managed to get in touch with David Robertson from Glasgow City Council who is in charge of the Molendinar Burn," Anderson says. "He couldn't believe his good luck – he'd found a woman who was more excited about it than he was. We watched videos of people walking through the Molendinar – parts of it are lined in blue brick, and there are vast overflow caverns. In its best form, it's just beautiful."
Anderson knew she enjoyed writing in her school days, but chose maths over English at university "because I thought it would get me a job". It was only after a career teaching maths, then computing, and raising her three children, that she returned to writing.
"The first thing I did was a short story which was in New Writing Scotland called "Pandrops". Iain Crichton Smith launched the book and he said it made him laugh.
"I remember thinking 'I've made Iain Crichton Smith laugh, I'm fine then!'" She went on to have several other stories published, wrote a short play for the 7:84 theatre company as well as a short film, Small Love, which earned her a Taps writer of the year nomination.
Her first novel, Driftnet, was completed in evenings and weekends while she worked as head of computing at George Watson's school in Edinburgh. "Some people play golf," she says, grinning.
Driftnet won Anderson a London agent, but a deal with a major publisher fell through at the eleventh hour. Her first three novels were published by Edinburgh-based Luath Press, and were critically acclaimed.
She is mellow about being a late starter. "It took me a while to get round to it – women's lives are funny, you've got to juggle so many things. When I got to 50, I made the decision that if I was going to do it, I had to do it now. My first agent asked my age and when I told her, she said, 'Oh good, because you have all this life experience.'"
That life experience has found its way into her books in many ways, whether it's the years she spent in northern Nigeria in the 1980s, which informed Dark Flight, or the training in internet security for schools which "sowed the seed" for Driftnet. And a time spent teaching on Orkney inspired Magnus Pirie, the dashing psychologist who joins the investigating team on Easy Kill as criminal profiler.
DI Bill Wilson is inspired by her father, who was a detective inspector in Greenock in the 1950s and 1960s. "I think back now on these things he said to me that I dismissed as a teenager. I used to think: 'He's just fussing', but I only wish he was here to say something now.
"I remember one night I was coming home on the late train from Glasgow University, and I became convinced a car was following me as I walked home from the station. When I got in, my father was waiting for me. He went to the window and gave them a wave – he'd got an unmarked car to follow me home. I remember thinking, for goodness sake, why didn't he just get a marked car to give me a lift?
"He never talked about his work. You knew if something really bad had happened because when he came home, he and my mother would disappear into the kitchen and shut the door. If it was a particularly bad thing, the whisky bottle went in too. Looking back, I realise that my mother was the strength behind the job."
Anderson is now producing a mass-market novel a year for Hodder – her sixth, Final Cut, is already in the can, and the seventh is on the drawing board. Does she feel under pressure? "Having had a job all my life, is it any different really?" Anderson smiles. "I could imagine that if you didn't have ideas that would be worrying, but when you've got a gang of characters and you're developing their lives, you've got scope."
She knew she was succeeding when her local fishmonger took her to task about Rhona's boyfriend. "He said to me, 'OK, Lin, she's got to get rid of Sean, because he's not good enough for her'. That's a wonderful thing, when the characters become very important to people. There is no description of Rhona anywhere, and yet I could sit in front of a group of people and they'll argue about it. At the end of the day, the crime story is about the people, not the crime."
• Lin Anderson's Easy Kill is published on 8 January (Hodder, 6.99).
Lin Anderson on forensic science
"People get hung up on the idea that forensic science is about tests. It's much more about problem-solving, about asking the right questions. If you've lost your car keys, and they're somewhere in the house, what do you do? Do you go in at the front door and check every single place from there? No, you use intelligent searching: where did I last see them? Where do I normally put them? Forensic scientists are as much a part of an investigation as a policeman. It's not about blanket testing, you couldn't afford to do that, you've got to be able to ask the questions."