I've been hearing bits and pieces about the case of Cameron Todd Willingham, who was executed in 2004 for allegedly starting a fire that killed his three children. Bob Herbert here gives a more detailed description of the case and why there are good reasons to think that Willingham was innocent.
This is an important issue for me because I feel it says something very bad about our justice system that the ones executed for crimes are overwhelmingly poor and minorities. It also points out that forensic evidence, or at least those that interpret it, aren't always reliable, and how highly unreliable eyewitness testimony can be. Do I want killers set free? Usually not, certainly not if they are still dangerous. But if the death sentence cannot be applied equitably, and the innocent freed, then the death penalty should be abolished.