I can't find anything on this.
Back when there was beheading of guillotine, an executioner would perform the execution.
When a firing squad was introduced, there is now multiple executioners.
Why is this? The only rational explanation I can think of is that it was so those people doing the execution would be unable to confirm who did the killing blow, thus they would have an easier conscience.
Thanks.
Your explanation is the essence of the answer. The main idea behind multiple people has a couple of explanations. The first is practicality. If we consider the evolution of firearms technology, we can see that guns did not always fire quickly and accurately. If a convict is to be executed by firearm, then handing one man a musket and telling him to shoot for the heart can be a long and drown out process. The words cruel and unusual come to mind when I picture a failed execution and one man having to reload his weapon in about thirty seconds just to give it another go. Even up to the early twentieth century, small arms did not (usually) fire quickly and the objective is to kill the offender immediately. The heart was what was aimed for and so if the target was missed then the convict would be left in excruciating pain while the executor prepared another salvo.
The role of the executioner that you brought up would be the second explanation. With let us say five men assembled, no one of them could say that they fired the fatal shot. This practice is further enhanced by one of the executioners traditionally being issued a blank round (a non-firing cartridge that makes noise but does not propel a bullet). The blank round when first introduced was problematic as a proper soldier can tell the difference between a live (real) cartridge and a blank, as the blank produces next to no recoil whatsoever. The lack of recoil in the blank cartridge meant that the executioner (or decidedly non-executioner) would be aware that they fired a blank and thus had lesser responsibility in the affair. In more modern times, what is called a soap round would be used which does produce a much more difficult to distinguish level of recoil. The entire false-bullet concept itself is linked to the use of firing squads in the military, which would be comprised sometimes of volunteers and sometimes of forced "volunteers." The blank cartridge supposedly encouraged the shooters to aim true, resulting in cleaner executions. While any modern use of firing squads comprises exclusively of volunteers, the use of the false cartridge still persists. I am uncertain if this is due to tradition or for some sense of morality, though I do not know why someone who volunteered for an execution squad would need to know that there was a chance they didn't kill the person in question but my theory would be in case they had remorse about the incident later in life.
In the United States, the use of firing squads as an execution method has been controversial in the mid to late twentieth century and early twenty-first century with the method falling out of favor due to increased popularity of lethal injection, but is currently resurging somewhat in places such as South Carolina. The last use of the firing squad in the United States as judicial punishment was in 2010 in the case of Ronnie Lee Gardener who selected the use of firing squad as an execution method.
Firing squads go back a long way, probably as long as there were guns. In the book Discipline militaire (Military discipline, 1592), Guillaume du Bellay, a soldier, military historian, and diplomat (1491-1543, the book was posthumous and was attributed to him), talks at length about military justice in the French army during the times of Francis 1.
In Book 3, Chapter 17, he describes the complex process used to judge foot soldiers (it involved 3 juges and secret votes using balls and jugs). There are four methods of executions: "Cutting the head", "Hanging and strangling", "Running the gauntlet" (in French Passer par les piques), and "Being harquebused".
In the first two cases, the condemned man will be delivered to the provost, the head military judge. For the latter two:
this task will belong to the soldiers, and to do so said Convict wil be handed over to the Band Sargents [a Band was a military unit]. And for the first execution to be carried out solemnly in the Corps, it will use the soldiers of the first Band, and the second execution will be done by the soldiers of the second Band, and the following ones by the other Bands, so that each Band has its turn.
Artist Jacques Callot did a graphic image of an arquebusade (1633): the execution is carried out by two harquebusiers facing their victim, blindfolded and tied to a post. Near the condemned man are three bodies lying on the grounds. Three harquebusiers behind the firing soldiers are preparing to shoot the next man, who can bee seen on the right of the picture in the foreground (Lormant, 2010).
An example of 16th century arquebusade is provided by the memoirs of Spanish officer Bernardino de Mendoza (published in 1592). In 1567, the Duke of Alba was sent to Brussels by King Philip II to tackle a protestant rebellion. While there, a Spanish captain convinced two other officers to desert with their men and join the French army. The three officers were soon caught:
And then the Master of Camp Julian Romero & the Captains sentenced three of the new captains to run the gauntlet, and to be harquebused, a sentence that is customary in the Spanish Infantry when the crime of the soldier is of such quality that it is necessary that the whole nation can feel it. So the companies left by the door of Couberghen in the countryside where they formed a squad, and they harquebused the chevau-léger as he was tied to a post, being the most guilty, and forgave the two other soldiers who had been seduced by him and pushed to suborn the Regiment's companies. Once justice was carried out, the Duke called the Master of Camp and Captains to which he made a harangue that can be summarized as follows, that after such an examplary justice, which they had carried out, everyone would know how strong that justice was, as it had been accompanied by clemency, shown by the forgiveness he had shown to the two other soldiers who would be particularly obliged to him, as they owned their life to him. And that the Spanish nation, thanks to such an incident that did not usually occur, could understand by the rigour of this punishment that one kept a watchful eye on the soldiers, so that they did not abandon their ensigns for some occasion (the thing being of great importance for the conservation of the military discipline.)
These early descriptions of firing squads show that they were already well established in the codes of military justice in European armies in the 16th century. We can see in both cases that execution by a firing squad was closely linked to the gauntlet, a military punishment that may have older origins in ancient Greece and Rome. Unlike hanging or decapitation, which required an executioner, those methods were carried out by soldiers themselves, and as notes Mendonza, were used for crimes specific to the army (ie not for things like thievery).
Justice of that time was all about being examplary: using soldiers to execute fellow men who had failed their military duty drove the message home that this was not ordinary justice, but one meant for soldiers who had engaged in treasonous acts.
The Jacques Callot engraving cited above includes the following caption:
Those who, in order to obey their evil genius, fail in their duty, use tyranny, enjoy only evil, violate reason, and whose treacherous actions produce a thousand bloody uproars in the camp, are thus punished and shot.
Now, in later centuries, it may be that the firing squad was meant to dilute the responsability of the individual soldier. But the initial goal was to impress their military duty upon regular troops, by forcing them to kill their own comrades. A further point was that, being a military execution carried out by soldiers for military crimes, death by firing squad was perceived as honourable (Marshall Ney was allowed to give the order to fire for his own execution in 1815). As wrote a legal analyst in his analysis of the Belgian military code in 1870:
Death by arms has never been considered infamous; it is not considered infamous to die arquebused, because it is at the hands of soldiers, who are honest people.
Of course, firing squads have also been used for the mass executions of civilians, but that's another debate.
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