Capitol punishment does not work as it is now. Punishments must be public, swift and severe in order to deter. Public hangings deterred.
Pay per view electric chair a week after your last appeal...say give you 1 year tops to finish the process. Now THAT would work.
Of course, the innate flaws to our "best attorney wins" court system creates the potential in which innocent people may get executed before the time in which their innocence may be proven. This is the unfortunate finality that comes with capital punishment. But capital punishment can work. However, without swift, severe punishment that is viewable by future criminals, capital punishment will not work, and does not work in our society (20 years on death row? ridiculous)
I found myself torn in the case of Tookie Williams recently on this very topic. If Tookie was executed 23 years ago, there would not have been public outcry to save him. Sure he maintained that he was innocent of the murder of the 4 people he was convicted of. But who really believed it (clearly not the jury), and furthermore, that was simply the one crime he was brought to court on. God knows you don't form one of the most prolific gangs our time has known without taking out a few people in your way, and a few people for the hell of it probably too. Beyond that, the Crips that he founded have gone on to kill likely in the thousands. So he should have been executed (provided you believe in capital punishment to begin with), no question, and it should have been a walk out of the court room straight to the chair.
But our system is flawed, we let him sit on death row for more than 2 decades and during that time he may have rethought his life. He did some great works trying to use his position to influence kids to make the right choices, the choices he didn't make. Now we choose to execute someone that is in the midst of making a positive influence of our kids instead of the thug that brought many children to hell with him.
If you execute him in 1982, many good works don't get done, but if you do it publicly, you may send a more real message, and save many kids and their victims for years to come. After 20 years, we probably shouldn't have executed him at all. It was a waste, two fold.