My story currently begins with the main character being attacked by a group of kidnappers and violently maiming/killing them with a tire iron. This happens mere paragraphs into the book, and there is currently little characterization before this. My question is, should I characterize the main character BEFORE he gets attacked, or AS he's being attacked. I kind of liked the second approach, because it allows the book to start with action and you can learn a lot about someone through their actions. HOWEVER, I think that if you knew the character before this incident, it would have more impact, and the scene would be less broken up. And if I do decide to go with the first option, what are some good scenarios where I can sneak characterization in without it being blatantly obvious?