Part three of KUOW's series on the state of execution examines the mechanics of execution.
Fair warning, this piece is highly informative but not always easy to listen to due to its graphic nature.
In Washington state, there are two options: hanging and lethal injection. Fascinatingly, reporter Patricia Murphy draws out some of the ethical issues involved.
The state divides the tasks into as many parts as possible so no one worker feels responsible for the execution. Also, in the case of lethal injection, three shots are given: The second is a paralytic; this makes the execution aesthetically peaceful for those watching, but from blood work done in autopsy, there is evidence that those executed feel pain even though they cannot move or communicate it in any way.
Like I said, not an easy listen, but full of good information if you're up for it.