Unfortunately, it is not common sense. Innocent until proven guilty is a very modern concept and still not practiced in much of the world. Human nature is tribal, we trust (or don't want to contradict) members of our groups, and we get a kind of a rush from "othering" people and ostracizing them, especially in a mob.

It takes work to protect the integrity of our justice system. This applies to the members within it and for those outside of it--neither should sacrifice or attack its credibility for short term political or personal gain. It also requires proper education that focuses on the good, not just the failings.

Looking at several DNA cases - guilty, until proven innocent.