There have been a lot of books written by criminals, and I catch myself wanting to fall into the same trap- they should be read, but they should be read with guidance. That's silly. It offends me when a power group says it about the bible... but I catch myself wanting to say the same thing.
People, the people who buy and read books are largely good people. They know good people. Consciously or not, they extend their assumptions about the people around them to authors.
Criminals, especially those doing serious time are not good people. They have gone into that place where they can kill or rob or sell drugs (the rapists almost never write books, or if they do they leave the rapes out) and are okay with it. When they write the books, they want you to be okay with it, too.
Violent criminals do a lot of mental gymnastics to justify their crimes. It takes a lot of mental gymnastics to rationalize sodomizing an eighty-year-old woman or stabbing an eleven-year-old girl or blowtorching another criminal to death. But not only are they good at living with themselves (most like themselves and some will brag about their stabbing a child as a proof of iron will) but they are good at getting other people to be okay with it as well. There is a reason that even after a savage, vicious killer dies resisting arrest his family will go on TV to say he was a "...good boy." It's not just looking for a settlement. Some really believe it.
They are master manipulators. It is how they survive. And the ones with the skill to write, to really write, are better at manipulation. Literati seem to want to believe that beautiful writing can only come from a beautiful soul. It's not true.
So I will, reluctantly, include a few books written by criminals in the bibliography of "7". But read them at your own risk. Don't read them for how the criminal sees himself, his victims or the world because he will almost surely be lying about that. Read for how he manipulates you, the reader. How he convinces you that he is either the victim, the hero, or both. How he gets you to question your ethics... even though you have never murdered, robbed or raped.