After liberals created gun-free zones in the 90s and the result has been many dozens of school and public building deaths, it amazes me that people think another gun control measure will finally make criminals stop killing people, especially in gun-free zones. I'm not sure why they keep pushing them. Also, the reintroduction of "Old Sparky" would have little effect, either. Wackos don't care about dying and criminals don't think they'll be caught. The death penalty as a deterrent isn't effective. As a punishment to remove psychopaths from society, so few are killed that it also has little effect. Make deep dark holes and throw them in. Less expensive and less controversial.
I'm unsure about the penicillin reference. I know that in military medicine, its invention lowered the rate of deaths due to infection a great many times.