Have you ever heard the writing advice, "show don't tell?" The idea is that you show the reader the plot, the secrets, and the message that you want them to take away from your novel without writing out the words. Many readers prefer to have their own perceptions and create their own picture of what your main character looks like, what the villain looks like, why he does the things that do, and perhaps the entire context around your novel. If you feel that you have to explain everything, you may not have a best-seller on your hands. If you explain everything, the reader isn't able to draw their own conclusions as they're being told something constantly.
You are taking away their freedom to interpret your story the way they want.
Many of the major works throughout English literature provide plenty of freedom. Many of these novels were open to interpretation, which allowed people to have different opinions about how, why, and perhaps even what happened in the story. This is why they are often part of course curriculums in schools. You should keep this in mind when crafting your crime novel, especially when it comes to your villain.
Motive is important but not your job to reveal
It is important that your villain has a motive for why he does the things that he does. A person doesn't go out and kill somebody just for the sake of killing someone. It's important that you provide an explanation as to why the killer did something, particularly if it pertains to the protagonist.
But if you feel that the villain has to explain why and how he did what he did, you have to rethink your story altogether as an author.
If your villain has to explain to the protagonist why he killed someone or what he did that could have hurt the protagonist, then your story isn't developed enough. In this kind of scenario, the villain is telling the protagonist what he did and why he did it.
The whole idea is to show your reader – and possibly your protagonist – why the villain does what he does. You really want to avoid this kind of situation, as the villain may come out of nowhere. A similar situation would be if you had a crime novel and the killer kill someone just for thrills. There is no motivation, there's no reason as to why the protagonist is even in the story and your plot will seriously lack any sort of connection and cohesion.
Remember to wrap up the loose ends
The idea is that when you craft a novel, all of the little puzzle pieces will come together. The protagonist will slowly figure out why he's the victim of something and why the villain is targeting him. It's important that you tie up the Loose Ends including the subplots before you wrap up the novel.
When all of the puzzle pieces slowly start coming together, the protagonist can see the full picture. But it's also possible that it is a friend of the protagonist that sees the picture first and has to tell the protagonist what is happening. The key is not to let the villain carry the load, as the villain has committed a crime, has to clean up the crime, and is feeding information to the protagonist as to why and what.
Have you ever had your villain explain to your protagonist why he committed a crime? How do you think that kind of novel would work out?
