Fiction by David Baldacci.
This book was the beginning of a Baldacci series about a white-hat assassin (there's an interesting concept) called Will Robie. It's from a few years back, so there are already a few more books written about him.
I enjoyed this book, but I'm not sure if I'm interested in more books about this character. The whole good-guy-who-kills-people-conflict was a little difficult.
I also read recently by this author: Memory Man