IT'S only at the end of our hour together that Louise Millar tells me about the time she was arrested for drug smuggling. We've been sitting in the Golden Lion Hotel in Stirling talking about her criminal motives. The restless childhood, the fears and anxieties, her familiarity with female murderers. All the whys and wherefores that led her to her criminal present.

And then, in the middle of telling me about a pointless temp job she once had, she adds: "Oh and I got arrested once."

What? Come again? "No I'm not going to go there. I'll get into trouble …" She hums and haws and finally tells me more. "Oh go on. I'll tell you. I got taken away by the police in Ecuador for suspected drug smuggling. That was pretty blooming scary."

Well, yes, I can imagine, I say. "But it was the woman next to me," she explains in case you're thinking "no smoke without fire". So hold those visions of Millar the drug mule.

How long were you in custody for Louise? "About 20 minutes. It was the scariest 20 minutes of my life. I was so scared. That's probably why I write crime novels."

Ah yes. There's the plot twist. She's not the person I've maybe hinted she was. The truth is Louise Millar is a married mother of two girls who lives in London with her headteacher husband Andy, loves music, has a background in magazine journalism, loves holidaying in the middle of nowhere and is now one of Scotland's growing expat crime writing community.

She's in Stirling this afternoon ahead of an appearance at this year's Bloody Scotland festival. There's a new book, City of Strangers, her fourth, to talk about. And so she's chatting to me about her Glasgow childhood, her love of Nordic noir, her days at Kerrang! magazine and the time she met Elvis's guitar teacher.

City of Strangers is her first book set – at least partly –in Scotland. In Edinburgh to be exact. And it marks something of a departure for her. Her previous novels have been claustrophobic psychological thrillers. This one has a wider remit. It follows Grace, a wannabe photojournalist, around Europe trying to find the answers to the person she has just found dead in her home when she and her husband came back from their honeymoon. Lots of excuses to pop over to Paris for research then. "It really was," she laughs.

Near the end of the book Grace is driving through the French countryside and thinking to herself: "Never in her life had she had such a strong sense of knowing exactly what she was doing." The question is, Louise, when it comes to writing does that describe you too?

"Yes," she says after a minute's consideration. "I think it is. I was not someone who ever thought I would write and I took a long circuitous route to being a writer. I really didn't start writing as a journalist until I was well into my thirties and didn't write any fiction."

But here she is. Four years ago she published her first novel, The Playdate. She was 46 at the time. Sometimes you need to take the long road to reach your destination.

Millar grew up on the very edge of Glasgow, in Waterfoot. Childhood memories are of running through fields and playing by the river, of a huge extended family and music everywhere. "Our house was the party house," she recalls. "A lot of my family were very musical. My grandfather was a concert hall singer and my great-grandfather on the other side was also a singer and one of my cousins was in a band called Slik. Do you remember Slik? Midge Ure?"

Millar played in bands herself as a teenager and at college. "They were pretty rubbish but they were a lot of fun. One of my songs was quite famous at the Oxford Free Festival scene," she says with mock pride.

By then, though, she had long left Glasgow. Her teenage years were spent moving around every couple of years as her father kept changing jobs. It wasn't witness protection, was it? "No," she laughs. "I'm really sad we left Scotland but you have to look for the positives and I think it's probably what made me a writer, because when you're always a new person then you're always observing people to work out what they're like before you start to make new friends. I think you probably get hypersensitive to the nuances of how people communicate."

It gave her an insight into psychological anxiety too. Her own. "It was something I really resented in my late teens. I had a really weird accent and my clothes were a mix of punk and a bit of hippy and I didn't really know what I was at all. I dropped out for five years. In and out of college. I went to live in a hippy commune for a couple of years. And it was when I met my husband that I got myself sorted out. He's an energetic mod. I was a hippy. We had a bit of a fight over my penny whistle. It was him or the penny whistle."

Her husband Andy was also from Scotland and maybe, she says, "there was a sense of finding someone from home". They eventually settled in north London and Millar pursued a career in magazines, more because of her love of music than publishing. She started off working for that heavy metal Bible, Kerrang! "It was brilliant," she says. "I was very, very shy and I turned up on the first day and it was bliss because they played very loud Metallica and Pantera all day, so you didn't have to speak."

On her first day she ended up on the carpet making a cardboard castle with the editor. Nuts, she says, but fun. She spent nearly 20 years working on it and other music magazines, Smash Hits and NME. She was always the girl in the corner keeping herself to herself.

And then she went with Andy to America for six months while he worked on a PHD on the writer William Faulkner. While he spent his time in libraries reading Faulkner's "dusty old love letters", she began to travel around, take pictures and keep a journal. "I stumbled on this little world in Mississippi. People who had known Elvis when he was a child."

The writer might have been born then. She turned that experience into articles when she came home and at 35 got a job on Marie Claire. (That's why she was in Ecuador at the top of the page.) Often, she would be interviewing women who had been affected by violence or responsible for it, up to and including murder. At some point she wondered if all this experience could feed into fiction.

It's the everyday fears she finds fascinating. Like who's looking after your child in The Playdate, for example. "As a writer I'm really interested in psychological terror. Most of us are not going to be affected by violent crime. But I think most of us at some point in our lives have come across a relationship that is psychologically damaging.

"I like to create those situations where people are under threat and then explore how you get yourself out of that. How do you survive that?"

Reading about it, she says, might act as a form of reassurance. And there's no shortage of readers. Or writers for that matter. Millar belongs to a 17-strong collective called Killer Women.

Crime fiction has always been female friendly. Indeed, many of the most famous names in the genre are women after all.

"There's lots of theories that women grow up being made aware of fear from a much earlier age. And maybe that's why we explore those fears," suggests Millar. "I think we're always surprised that women write violent crime. We're surprised so many women read them. But why are we surprised? We don't talk about why men read or write crime novels.

"Do we accept women have violent impulses as well or are we socialised to think that we don't or we shouldn't?"

That's the patriarchy for you, Louise.

There's another book on the cards and if you ask her for an ambition she would love someone to take one of her books and turn it into a movie. She thinks she's finished with domestic noir for now. "When I wrote my first books I was more in that mind set. Now I'm travelling again and I travel a lot and I'd like to bring that into my next book."

Louise Millar is going international then. Though she might possibly give Ecuador a miss.

City of Strangers, by Louise Millar, is published by MacMillan, priced £12.99