This review and others are posted at Inspiring Insomnia.
Let's get one thing out of the way: I know this is a work of fiction. I read (and love) books about zombies, vampires, and other outlandish topics. Project Cain takes a topic that is actually real - cloning - and then makes a giant leap forward. But that leap didn't make a whole lot of sense.
In real life, animals have been cloned, including at least one instance I can remember of a person cloning a beloved pet. It's not too far-fetched to think that one day, setting aside all of the ethical implications, a human might be cloned. In fact, I wouldn't blink if you told me that U.S. scientists were holed up in some secret government facility in the middle of the desert, plotting to develop an army of clones. So who should we clone? A genius like Albert Einstein? A musical prodigy like Beethoven? A humanitarian like Nelson Mandela? How about...famous serial killer, cannibal and necrophiliac Jeffrey Dahmer? And here we have Project Cain. In Project Cain, the government has decided to build clones of famous serial killers including Dahmer, Ted Bundy, and others.
Let's think about we know about serial killers. They're sociopaths and/or psychopaths. They have no conscience. Rules and laws don't mean a whole hell of a lot to them. Now, what do we know about soldiers? They follow rules. End of story. How in the world can you expect to control a serial killer? They kill because they like it. Soldiers kill because they're ordered. Also, the reason why we know the names of all these serial killers is because...they got caught. So, they're sloppy and careless, to boot. I don't think I'd want people like this in my army.
But here's my biggest problem: Are serial killers born, or are they made? Or maybe it's a combination of both? This is the most critical problem with the book's theory. Perhaps some serial killers have something in their brain chemistry that ensures they are destined to kill, no matter what their life experiences. But surely this is not the case for all of them. If nurture plays even the smallest part, the whole "let's make an army of cloned serial killers" idea falls apart, since it's absolutely impossible to replicate every life experience of a person. As I read the book, I kept waiting for this issue to be raised. Finally, late in the book it was very briefly mentioned and then seemingly dismissed.
At times I asked myself: Where's the story? It reads like a mixture of a wide-ranging variety of history lessons and a fictional story, with the story seeming secondary. Much of it was interesting, in particular the information regarding experiments the U.S. conducted on its own unwitting citizens, but it doesn't add up to an interesting plot. The story constantly stopped and started in order to provide these info dumps. When I finished the book, I'd learned a lot about serial killers, but I could have looked it all up on Wikipedia.