We rarely know the whole story. What we get served is rather an advertised sensationalism, a specific view that is more appealing.
Humans are very troubling beings. If one goes back long enough, anyone can be justified (more or less) for their actions. We all want to believe that we are good people. Thus, we excuse our bad deeds as a defense from unfortunate events.
This series (for me) discovers perfectly the tragedy of the human condition