There's a real emphasis on being witty in Scotland, even in crime novels.

I'd read so much right-wing crime fiction where they find the evidence and shoot the bad guy - I thought there must be another approach.

I have two children. They are more fun than anything in the world, and it's more immediate fun than the hard slog of writing.

In the 'Garnethill' trilogy, people always forget that Maureen O'Donnell's dad was a journalist and she did art history at uni and her brother did law, but no-one ever thinks they're middle-class - they're just working class because they speak with accents.

In prose, leaps of logic can be made while the protagonist thinks about things and arrives at conclusions. Even with voiceover, there's no real way of having an inner voice without it taking over the entire story.

Most of the people who write to me are really clever, really engaged. They just want to say that they have read my book and liked it.

Crime fiction is the fiction of social history. Societies get the crimes they deserve.