For every genocide ever committed, do you think there were voices of non-violent resistance?

In a full-blown genocide, most ordinary people will end up attempting to flee or hide. But genocide usually takes a while to prepare, until it starts happening, and then happens very quickly. The problem is identifying a genocide before it occurs. In most cases, I would deem non-violence to be the best answer, but in a case of genocide, when one group has decided to exterminate people, it is too late. Effective non-violent resistance has to occur before that tipping point.