Troy Davis and publically killing a potentially innocent man

I just have to post about this, even though I know millions of people already did and it didn't make any difference. I may just be one additional voice amidst many, but what happened last night was a complete and utter miscarriage of justice. Troy Davis may have been guilty, but he also may have been innocent, and with the amount of reasonable doubt of guilt in this case he should never have been executed.
This is not even a question about being for or against capital punishment, it's a question about killing someone who may be innocent. It would have cost the state just as much money to keep Troy Davis in prison for the rest of his life as it did to kill him last night, so why did they still go ahead with it. Why did the Supreme Court deny the stay of execution? How could they decide that Troy Davis needed to die, when only a few months ago, Casey Anthony was released in Florida, because there was reasonable doubt of her guilt? Troy Davis' conviction was also solely based on witness testimonials, many of which were recanted or contradicted. So why go ahead and kill him?

I'm disgusted.

Read more about Troy Davis here.
Amnesty International condemning execution