Michael DeDora has an excellent post on what Craig Hicks does or doesn’t have to do with vocal atheism and what vocal atheism has to do with being a decent human.
…as merely a position on whether god/s exist, atheism is no guarantor of moral behavior, and no guarantee should that be expected from it. Stalin, Mao, Pol Pot, and many others — apparently now including Craig Hicks — are atheists who have killed. A person’s atheism only tells you that they reject the idea of a god. It does not tell you about the rest of their character, which, as with all people, can include a very human but very misguided hatred. I guarantee some atheists will continue to do violence in the world so long as both atheists and the world exist. Why atheists continue to defend atheism at the expense of a broader moral and philosophical framework remains a mystery to me. This event should remind us that mere atheism is not enough — that for humans to find decency and sustain it, we must construct and nourish moral frameworks that engender complete respect for our fellow humans regardless of their beliefs on religion or gods. Hicks was an atheist, but he was apparently not also humanist. Humanism provides no shelter for such hatred and murder.