OK, all issues of morality, justice, gov't ineptitude aside...
Why not slip the condemed a "rufie" or other "mickey finn" in a meal when TPTB decide the time has come without all of the hype?
Then shuffle the unconscious inmate off to a gas chamber and introduce Carbon Monoxide until the convict expires. Cremate the remains and dispose of the ashes.
Cheap, painless, effective.
I think all of the ritual and signifigance "We, the people" (and the media) create surrounding an execution is ridiculous.
Send the victims and NOK a form letter advising that inmate X was executed on whatever the date is.
End of story.