If the question were slanted, it would be framed either the way you are trying to frame it or framed in terms of innocent people being executed, but it's not.
It's not a deterrent because most of the time, criminals are acting in the moment or under compulsion, not thinking of consequences, or they think they won't get caught.
It's more than likely they figure they'll escape the death penalty, or it will take so long to carry out they will die of natural causes first which has happened here a few times.
Let me handle the death penalty cases in this country, and I guarantee you I could cut the murder rate by at least half. A strong enough deterrent works every time it's tried. After all, are you worried about what's going to happen to you 15 years from today? Most people aren't and criminals feel the same way.
You are assuming a number of things. Not all death row cases have DNA evidence to support them. A great many rely on eye witness testimony which can be notoriously unreliable. Also, they aren't necessarily the worst of the worst. The crimes vary by state law. The death penalty is also grossly unjust in its application, with disproportionate numbers of minorities and poor people getting the death penalty for the same crimes another might get a prison term for.
Wrong. Remember that minorities murder way more people than whites per capita. In the US, you are six times more likely to be murdered by a black than a white, and they only make up about 13% of our population.
The death penalty is seldom if ever given to a suspect of questionable guilt. In most cases, it's the jury that makes the recommendation and the judge who honors it. What murders take place where they are able to fool forensic scientists? Those people can find a single strand of hair on the victim or on the grounds which they were murdered.
Race of Death Row Inmates Executed Since 1976 | Death Penalty Information Center
We have a lot more Flintstones then you might think, communities with lead problems. And other problems. WV has had at least two serious water problems with chemical spill contaminstion, one of which resulted in instituting new regulations.
Would your tenants rent if you told them you water was undrinkable due to high levels of lead and maybe not even safe for bathing?
Of course not, but in too many cases the water is fine and they institute unnecessary regulations. Could water always be cleaner or better? Sure it can, but at what cost?
If an area has problems with their water, it's up to them to find a solution and perhaps request federal help if needed. But again, that's up to them--not Washington DC.
Years ago the feds decided that our air wasn't good enough for them. Okay, so stay the hell out of our city! No, instead, they forced regulations on us in way of vehicle inspections. So we had to spend (and are still spending) millions and millions of dollars to keep the feds happy. Ten years after the program started, they measured the air again, and found no change from ten years early. So what did they do? They extended the program.
Money wasted to solve a problem that wasn't there. That money could have been used for much better things and more necessary things.