Chris Hayes highlights this problem well:
Okay I didn't mean to debate the merits of capital punishment in this post, but I do think the fact the death penalty was on the table helped to sensationalize this case in a way that wasn't needed. And at the end of the day, reasonable doubt is there for a reason. Of course it's too bad only those with enough money to pay for a team of lawyers can make DNA evidence seem like some strange voodoo while innocent men are put to death for crimes they didn't commit, but that's besides the point. Reasonable doubt may be damn expensive, but it's also important.
Oh wow. I'm all ranty today aren't I?