Well, the book is a republishing of Six Six Six: The FBI Agent, the Mob Killer, and the Bloody Alliance the Feds Tried to Hide which was published in 2008. The current title is much better, IMO.

I don't think that it reveals a ton of what wasn't already available in FBI files, court reports, etc., but it does put it all together for us in a neat package.

So, yeah, kind of like things that have been known but just a little more detail.