I used to be a "hang'em high at noon" kind of guy. After seeing what really happens behind the scenes in death row cases, I changed my mind.
The death penalty in the United States is a system filled with a bunch of people trying to make names for themselves. Capital cases make judges and prosecutors look tough on crime. The cases make the defense attorney look like someone trying to save a person in a burning building. All the while, truth and justice suffer.
In my cousins case, there was a judge and prosecutor that was up for reelection in a small Arizona county. The Judge had a homosexual son, and had writings telling his son "he hoped he would die with the rest of his faggot friends" (yes, my cousin is gay). The public defender had never worked on a capital punishment case, and was a real estate/probate attorney. IIRC the defense was given $500 by the state for a private investigator. In Arizona, you don't have to kill someone to be on death row. In my cousins case, he was with a guy that killed someone. The kid that shot two people, got 25 to life and my cousin got death row because he was older. The stories go on and on.
There are many on death row that are scum bags, I agree. There are also many that are innocent of the crimes also. Since 1976 when the supreme court reinstated the death penalty over 900 death row inmates have been free'ed because they have been proven innocent on appeals.
The effect on the families on both sides of the cases is tremendous. My cousins case cost my aunt and uncle hundreds of thousands of dollars, and all of there retirement years fighting for my cousin.