I finished reading "In Cold Blood." What can I say about the book that hasn't already been said? It's fantastic.
In any case I'm haunted by the book, and I've been thinking about it a lot. What haunts me is not the crime or the minds of the criminals but a theme that manifested itself towards the end of the book. The theme of revenge and justice, how they relate to each other in the minds of people that have been wronged, and how they can be inappropriately conflated.
In the book Perry said he killed the Clutters because someone eventually had to pay for all the injustice he'd experienced in his life. After his crime he didn't feel happy or sad about killing the family; he felt nothing. Perry's revenge reaped no sense of justice.
Dick asked right before he was to be hanged if any surviving members of the Clutter family were present at his execution. When he was told no Clutter family member was there he voiced that he failed to see the point of his execution. In Dick's mind justice failed because it reaped no sense of revenge.
The theme is especially poignant given the current world order. Everything that was allowed to happen to get us where we are now was because people, myself included, confused revenge with justice. They're not the same, and we should all take caution in the future to make sure we don't confuse the two, or allow anyone to convince us the two are the same, again.