The reason people like crime fiction is because they get a "sense of danger simply by sitting in their armchair," says expert Barry Forshaw, who will be talking about the genre as part of Watford Big Word Fest.

The 60-year-old from Islington says: "You get a vicarious pleasure from reading about it in a book. It's too dangerous to do it in real life and people don't want to put themselves in that situation - so you read about it. More than often though, crime in a book gets solved, but in real life, you here about the countless crimes that never get solved, which means that those affected don't get closure."

Barry, who is originally from Liverpool, has published several books about the crime genre including The Rough Guide to Crime Fiction, Brit Noir, Nordic Noir, Euro Noir, Sex and Film, which all look at well-known crime novels and films of that particular country.

He says: "Raymond Chandler's The Big Sleep, that's what started my love for crime fiction. When I was young, back in Liverpool, I used to go to the cinema two or three times a week - it's what you did in the '60s.

"Obviously I love crime films, but I also enjoyed action, comedy and arthouse films - an interesting and important one for me was La Dolce Vita. Most people who love films, love all the genres.

"The one film that made a big impression on me," Barry adds, "was Psycho. I was 12-years-old and I snuck in to see the film, I didn't actually think they would let me in, but they did. It was certainly frightening but a great film."

When Barry was 20 he moved down to London to work for The Independent - he previously worked at his local newspaper - the Liverpool Echo - and it was while working in London that he started to specialise in writing about crime fiction, saying, "When you begin to focus on one thing in particular, you do become very knowledgeable about it."

He explains: "When authors, crime writers came to London they came to me and that's how it first started. We had a Scandinavian author come over and from that I started looking at crimes in those countries. There was also an actor, who played a role in a Scandinavian TV series, which was actually quite popular over here and they were quite shocked about that. But it all led me to go over there, speak to authors, writers and find out about the culture, society and the crimes over there.

"After Nordic Noir I also started looking at other European countries but then Ian Rankin, who's a Scottish crime writer said to me, 'you are British, why don't you do more British writers', so that's what I moved on to.

"I have done the greats like Agatha Christie but now I'm looking at living crime authors such as Mark Billingham."

Here Barry talk about his work at Watford Central Library on April 13. Details: 01707 281533, hertsdirect.org/libraryeventtickets