Ain't No Test for the Wicked
Justice is a heavy word. It has meant life, death, retribution or disappointment to whoever was in justice's crosshairs, and the methods to ensure that justice is fulfilled is as varied as the crimes that man can come up with. From treadmills to foot whipping to branding, ways to punish the guilty were legion. Frequently, the crime a person was found guilty of was sufficient for execution, and the methods of execution could be, in themselves, punishment - rebelling against a king could see the ringleaders being burned alive while the common rebels were merely beheaded, for instance. A harrowing example was what the leaders of the Munster Rebellion went through; the punishment of scaphism is another. Modern-day governments trend away from painful, public executions, with the United States of America having five legal methods of execution - lethal injection, electrocution, gas chamber, hanging, and the firing squad.
A person is submitted to these punishments in the United States of America after they have been found guilty of crimes by either the determination of a jury or, if the defendant refuses, solely by the judge. The judge presiding over their case then gives the punishment of death for the crimes they have been found guilty of. Integral to this process are prosecutors and defense attorneys - the prosecutors always work in service to the state, while defense attorneys may be privately retained or doled out by the state. Prosecutors have the role to find the defendant guilty, despite any proof to the contrary; defense attorneys have the role to find the defendant not guilty, despite any proof the contrary. Tying all of this together is usage of the phrase "not guilty", as opposed to innocent- for though the defendant is presumed innocent, the evidence and accusations levied against the defendant may not be solid enough to constitute proof of guilt or innocence.
Unless you are a sociopath, it is a very heavy thing to condemn a man to death. But practical problems in archaic days made harsh treatment a necessity - having somebody steal your cattle could be a death sentence for you and your family, so to dissuade cattle rustlers, death was made a penalty; stealing and pick-pocketing is a constant epidemic in urban areas, so chopping off thieves' hands became a solution. Legal codes such as Talmudic Law, Shariah, and the Code of Hammurabi served as social anchors to maintain stability and ensure the safety of traveling merchants. The punishments for crimes committed underneath these codes, which would be considered barbaric in Western society, had to occur because the capacity for the state to prevent these crimes did not exist.
This is no longer the case. We live in a time and in a country with a relative abundance of resources and methods to dissuade crime. Our ability to track down and identify criminals with cameras, forensics, and DNA testing makes the scale of justice tilt more toward certainty than ever before. But "towards certainty" does not mean "certain", and we are ultimately no more certain of somebody's guilt than we are of their innocence. The verdict of "not guilty" being used instead of "innocent" is a conscious choice of phrase that reflects this - the usage of juries or judges does not guarantee that the correct verdict is made, and though juries are instructed to only come back with the verdict of guilty if there is no reasonable doubt, we know that doesn't occur.
A system made by humans and made up of humans is fallible just as humans are, and as much as we try to mitigate these fallacies by screening for juror bigotry and increasing funding for more public defendants, mistakes do happen. The reality of judicial error is why appeals court exists; the appeals process is also one of the reasons why keeping a prisoner on death row is substantially more expensive than not. Supporters of the death penalty might say that it is better to do away with the appeal process for death row inmates in the interest of killing them faster for the safety of greater society - this is an extremely reckless route to take in the interest of saving cash, and the danger of letting death row inmates live is far less than the danger of letting the government have free reign executing people. Concern about a government gone mad is the reason why the Thirteen Colonies broke away from the British Empire, and this valid concern should still resonate - as a jury is made up of fallible people, so is a government.
And it is the realization of our fallibility that is the reason we should abandon the death penalty, for as much as we try, innocent people are still found guilty. And it is a central tenet of our government and our culture that we allow the guilty go free in order to not imprison the innocent - this goes from the Article 11 of the Declaration of Human Rights through William Blackstone who stated that "It is better that ten guilty persons escape than that one innocent suffer" to Emperor Justinian declaring "Proof lies on him who asserts, not on him who denies" to God telling Abraham he would not destroy the city of Sodom if Abraham could find 10 good people inside its walls.
The death penalty prevents us from making amends to the wrongly convicted. And these false convictions do happen - sometimes through judicial error, sometimes through scientific error. Forensic hair analysis was a cornerstone of investigations until its accuracy was questioned, and in 2015 the FBI admitted up to 95% of cases it was used in favor of the prosecution. And while camera and audio recordings can incriminate the right person, they can be interpreted incorrectly by a jury manipulated by a convincing prosecutor and an overworked public defendant.
We should not ban the death penalty to spare those who have done terrible things. We should ban the death penalty because the government must be held to a higher standard. When we realize that we not only have both the ability and the history to put a man to death unjustly, we must adapt. We have the capacity to be beasts and the responsibility to be gods, and it is our burden to make sure the scales of justice balance. If the consequence of justice is that our prisons have a few more people in them that would otherwise be put to death, that is our burden to pay for.
If we want to stop time-consuming court cases and profligate spending on prisons, better effort would be spent on not imprisoning non-violent drug offenders instead of fearmongering for the death sentence. Unfortunately our current Attorney General, Jeff Sessions, has stopped the investigation into forensic hair analysis accuracy, wants to double down on the failing Drug War, and has shown a fondness for the death penalty - particularly for the (exonerated) Central Park Five and for cannabis traffickers.
In light of all of this, a maxim bears to be repeated - just because it is legal, doesn't mean it is right.