Reddit reviews Courtroom 302: A Year Behind the Scenes in an American Criminal Courthouse

>suggesting that the prosecution and the defense would somehow conspire together to get a particular outcome at trial

That all makes sense, right up until I read this book. The way the current system is working often results in the prosecution or defense either unwilling or, more often unable to play their roles effectively.

>the adversarial system has been used for about a thousand years.

And if you go back a thousand years, or even a whole lot less, one key difference is that the players are a whole lot less likely ever to see each other again. Even 50 or 100 years ago, a bad prosecutor or defense attorney would have a reputation that everyone in town knew about. A jury of your peers could easily include people who knew each other, if not the defendant.

Also, for the past thousand years jury trials do not have sterling record with respect to defendants who were just a little bit out of the community norm, whether because they're a minority or for some other difference.

I think you should read things that give you a bird's eye view of law and the justice system without getting into the nitty gritty. I always recommend Courtroom 302 to anyone expressing an interest in law.