Why can't we automate a gun or a tool that shoves a rod in a brain? I mean, howevs the controls are initiated now, we can just keep those and wire them to the new machine. Quick, effective, and super cheap (other than appeals). The current method seems like a super needlessly complex way of doing something very simple.
No one will suffer for hours or anything like that, no labs across the country producing unknown drugs, no worry about whether or not the component that paralyses the inmate allows them to feel pain or not, and no side effects. Just effective death.
If a state is going to have capital punishment, they should skip the Rube Goldberg device.
