I don't read many crime novels, or even watch that many TV shows that fit the genre. They've never really appealed to me for some reason - I suspect that's because my parents read/watch crime stuff almost exclusively - but I've been thinking about it recently, mostly because an idea for a sort-of-crime-novel has been brewing.
Mostly what I've been thinking about is the idea of the detective (or other police officer, but let's say detective) as the hero. Or protagonist. Yeah, protagonist is better. It's strange to me because, presumably, the villain is the character actually going around and doing interesting things. The detective just follows him and makes observations, not really doing a whole lot until, say, the final third when it all comes together and they apprehend the villain.
Is this why so many detectives are given complicated backstories or dysfunctional relationships? To make them interesting? I recently read an open letter, I think it was in the Radio Times, criticising the fact that there are no settled, sensible, content police officers on TV. And it annoyed me. Contentment is boring, we need drama and conflict. Without it, the programme would be dull and the fact that the villain should be taking centre stage becomes much more apparent.
The protagonist of my soon-to-be sort-of-crime-novel isn't exactly a hero. In fact, she's very much a criminal, but the story couldn't work from anyone else's point of view. It has to be her. She's not exactly a villain, but she's definitely the bad guy. And she's the most interesting character in there.