Another possible wrongful execution

For those of you who don't regularly read Arianna's massively successful Huffington Post, here's an article discussing yet another possible wrongful execution by the state of Texas:  De Luna Execution.  How many times must we catch wrongful executions or wrongful convictions and subsequent death penalty sentences before we begin really weighing whether our laws need to be re-examined???  Again, this is just one more nail in Texas's coffin for me.