Two recent polls indicate that Americans’ support for the death penalty is on the decline. In fact, support is the lowest it’s been since 1972 when the U.S. Supreme Court struck down death penalty laws across the country in Furman v. Georgia. Now 61 percent support the death penalty (a drop of almost 20 percent from the mid-nineties) but when given an alternative of life without parole, only 48 percent stick with death.

I can’t help but wonder if Troy Davis changed some people’s minds. Davis’s case – the fact that the State of Georgia executed Davis despite serious questions about his innocence – highlights why I changed my mind about the death penalty.

When a person is accused of a crime, they are innocent until they are proven guilty, and to be convicted 12 jurors must believe in their guilt beyond any reasonable doubt. Once convicted, though, that presumption of innocence gets turned on its head: a convicted person is essentially guilty until proven innocent. Proving innocence is difficult in most cases, but it’s an understandable requirement. Without that finality, courts would be bogged down with requests to overturn or revisit or retry every decision.

But what happens when someone has pretty good proof that they could be innocent? Say witnesses change or contradict their story or insist their original testimony was coerced. Or new evidence is uncovered that suggests a different person committed the crime. Unless that evidence meets the high standard of proof, unless like District Court Judge William Moore said in Davis’s case, it can be shown “by clear and convincing evidence that no reasonable juror would have convicted him in the light of the new evidence,” the conviction stands.

This means that only some of the people convicted of crimes they didn’t commit will be released from prison, while many others will complete the entirety of their sentence. And although this is a really uncomfortable fact, it’s one that we all agree to, at least implicitly, to keep our justice system running.

But the thing I find unacceptably uncomfortable, and maybe a growing number of Americans do as well, is that the same standard is applied to death sentences. Cases, like Troy Davis’s, can develop rather large holes, but those holes aren’t quite enough to meet that high standard. And unless clemency is granted by a Governor who might have to face reelection, that sentence of death is going to stand.

What originally got me thinking about the death penalty wasn’t the morality or the cost or the racial and economic bias or even the growing worldwide disfavor of it, although the more I learned the more troubling it became. What got me thinking was the system that supposedly works to protect life doesn’t revisit those serious questions of innocence before it okays an execution. When life – not just liberty – is on the line, you’d hope those questions would be answered.