I'm not a big fan of lethal injection. I don't think murderers should be killed in essentially much the same manner that beloved, suffering pets are euthanized. However, I can understand why someone would not want to be strapped to a gurney and would want to "die like a man" facing a firing squad. I'm not sure murderers deserve that kind of consideration.
A firing squad is a quicker, more humane death than the injections. A near instant death with perhaps a few seconds of pain at most? The gilloutine although medieval and bloody too is also humane for the executed in quick fashion. Injections, electric chair , gas chamber not so much.
Hang the condemned, it’s merciful and quick if done right, energy efficient and environmentally friendly.
They could even put a happy face on the hood.
Maybe I’m just weird but I’m thinking the best way to execute murderers is to drop them out of an airplane without a parachute somewhere over the Arctic Circle - say about 40,000 feet up.