When Gardner was executed, I remember commentators saying that the firing squad was the most physiologically distressing option for the executioners, because it involved direct sight of the target. Even then, they arranged lighting to make it as humane as possible for the shooters.
I saw a documentary in the 1990s about execution. I remember a couple of things. First off, someone whose job it was to ensure that the methods of execution were as quick as possible for the prisoner saying that is was really hard to “break a human body” (I remember that phrase) to the point that it will instantly cease to function.
Secondly, they explained the really complex mechanical and legal process involved in ensuring that the person pressing the button was not directly involved with the killing. There is an almost rube goldberg mechanism which means that pressing a button may, or may not, cause the death to occur. Generally, there is more than one button, one which is randomly selected to trigger the system. The buttons must be pressed at the same time, so there is immediate confusions to who set the system off. This is analogous to the firing squad having one live round and a series of blanks in the other guns.
In the case of the lethal injection (which this programme seems dot concentrate on), there are then a series of plungers and mechanisms that eventually end up delivering the lethal cocktail of drugs, in a strict sequence so that the prisoner is anaesthetised, put to sleep, and then killed.
Usually, the people who press the buttons are homeless who are in need of cash. No names are taken, cash is paid, and they are sent on their way afterwards.
So, there is legal and physical confusion over how each execution is administered. Each execution is recorded as a murder (as it has to be legally recorded as such), but is then logged as unsolved, and it remains so. The result is that states with capital punishment tend to have a higher rate of unsolved prison murders.
I’d expect some kind of mechanical device is devised which aims a gun at point blank range - with no “wriggle” factor. A press of a button and your prisoner is put to sleep, and shot. A head shot is preferable, but knowing the USA’s fondness for open casket funerals, aiming the the heart would likely be a better choice.
Well, this is a jolly subject.