We can take a position on this argument based on belief or gut instinct. But we're dealing with life, so certainty is warranted. Every time a life is taken by the government, that's us. The government is us. We can either endorse the act, or resist it. And when it comes to life, we should know what we're talking about when we make that decision. Because, every execution is sanctioned by us, unless we resist it.
The argument over the death penalty, once we get beyond the Biblical eye for an eye, needs to be buttressed by proof. Well, it seems proof doesn't really exist, on either side of the dispute. Don't believe me. I just did some research. Here's a report--a very balanced report from U Penn (2012). The report looks back at 30 years of research. In the very end, the authors offer a conclusion: "perhaps the primary lesson learned from the latest round of empirical research on the deterrent effect of the death penalty is that researchers and policy makers must cope with ambiguity".
That's not really enough to strap someone to gurney and take their lives--or put them in front of a firing squad. I think we need something a little stronger than "ambiguity", to take someone's life.
Great discussion. It will go on....But I guess you know where I stand in this argument :)