We already know exactly how to dispense the ultimate justice quickly and cheaply. Just use nitrogen. No one can object to using nitrogen (at least and still have any credibility left). Anyone who does outs themselves as not being against the method, but instead being against the state being able to execute at all. Nitrogen is approximately 80% of every single breath you take, unless you are on a ventilator that is furnishing a high-oxygen environment. Nitrogen is non-flammable. It is non-toxic, in normal concentrations.
It is only when you get high enough concentrations that it is any issue at all. Industrial sites that can have excessive nitrogen accumulation are well aware of this. If you walk into a room that is filled with a high enough concentration of nitrogen (95% or so), you will have no idea whatsoever that you are dying. You would just continue walking along, and then collapse after a few minutes and die without ever knowing what the hell happened. This is because nitrogen does not trigger the suffocation reflex. If you're in a room with nothing but CO2, you'll know you're dying because the body recognises the danger of too much CO2. It does not recognize the danger of excessive N2. How the hell could it, when every breath you have taken your entire life is saturated with almost 80% of the stuff?
Here's how such an execution would work. The person is wheeled into an air-tight chamber, and everyone leaves but the condemned. The O2 and other gasses are flushed out by feeding in N2 under positive pressure. You wait 15 to 30 minutes (just to be sure), then purge the air in the room to an exhaust on the roof and pump in normal air in it's place. You can have a gauge in the room that tells you when there is enough O2 for it to be safe. Then to wheel the body out and move on to the next.
No other special preparations have to be made other than to make sure that the room will reliably reach, say a 95% N2 atmosphere. You don't have to deal with poisons, or doctors, or anything else.
People suggesting firing squads, hangings, and any of the other more (I'll admit) emotionally satisfying options are just trying to muddy the water. All it does is make it more difficult to carry out the death penalty than it needs to be.
I have some personal issues with the death penalty, mainly because I have little to no faith that our government is even capable of actually administering actual 'justice' through our legal system. However, if you're going to do it, and I really do believe it it the appropriate punishment for some crimes, then you should just do the deed, and throw all the emotional baggage out the window.
Yes, the “suffering” of the accused has to be considered. At lest for a final closure for the family of his victims, witnessing the event is a therapeutic thing.
I guess you could have the digital O2 and nitrogen concentration meters visible to the inmate. Just so they cant bitch about having it being done surreptitiously.