It's book recommendation day, so here are two for you:
His books are part spy novels, part thrillers, and he was one of the first to introduce an element of realism to this kind of story. His name is Eric Ambler and he's the favorite author of my protagonist, Hugo Marston, and I even take the liberty of quoting Ambler in my own novel (which you'll have to wait for, obviously!).
No doubt I'll recommend other Ambler books in the future, but the first is going to be A Coffin for Dimitrios (also titled The Mask of Dimitrios).
One line synopsis: While vacationing in Istanbul, an English novelist decides to investigate the intriguing past of one of Europe's most sinister criminals. Trust me, there's waaaay more to it than that.
I love Ambler because his characters are so memorable, but without being caricatures. He puts "ordinary" people in bizarre situations and you follow along as they wriggle and twist and try to make sense of them. Or just escape them.
Here's a book for those of you interested in the mind of our most feared criminals, the serial killer. Not a story, it is an overview of the profiling techniques used to catch a few of the nastiest characters who have stalked the earth.
This book can irritate at times because the author, Robert Ressler, is well aware of his abilities and not shy about letting us know how awesome he is. That said, he's a pioneer in the field of behavioral profiling and you won't get much closer to multiple serial killers than this book.