The Lethal Injection idea was from interviewing a veterinarian who of course refused to implement it, as did every Medical Doctor in the USA because of fucking course nobody would touch breaking the oath in such a way with a ten foot pole. The result is a bunch of untrained amateurs carrying out the procedures and an extremely low success rate leading to unjust and unnecessary pain and trauma.
I imagine all the other methods they come up with to follow a similar series of events.