At least in the US, I believe a majority of prison inmates get there initially by means of gang violence, and all it's related crimes such as drug dealing and r

At least in the US, I believe a majority of prison inmates get there initially by means of gang violence, and all it's related crimes such as drug dealing and robbery. Most of these people will tell you that it's simply a way of life, particularly true for people on the edge of society with few other means for advancement. So yes, I think most criminals do believe their actions are just.