If a criminal gets a lethal injection they cannot be a repeat offender plus it saves society money as it cost a hundred thousand to house criminals, food, shelter, lights and guards and medical.
Think of it several hundred thousand per person!!!! a quick shot is a lot cheaper.
I have no problem with my tax pennies being used to build prisons and house murderers, rapists and nonces indefinitely. Comfortable in the knowledge that the notion that you should not take a life, extends to all members of society.
Have you not also considered the legal costs of putting someone on death row? As far as I am aware, a prison guards salary is a hell of a lot less than that of a lawyer.
It's the other stuff I'd consider a waste of cash. MP's wages/expenses, tomahawk missiles, identity cards etc etc