My link handed you every single "fact" yours did, in its original scientific paper as well as edited and paraphrased quotes - plus, you know, the analysis and the other studies and so forth your mass media article dismissed as "other scientists" and unspecified "controversy".
If you actually are about the facts involved, you will read them.
Here's another fact: the Illinois death penalty was suspended by the Governor of the State originally because DNA analysis had shown that more than one in eight of the convicted in capital level cases were innocent. Illinois was mentioned specifically by your "fact" purveyors as an example of murders that would have been deterred.
That means that a large share of the supposed deterrent effect reported by your heroes of science there (actually, not measured but extrapolated under dubious assumptions) was obtained by having the State kill falsely accused people - disproportionately, for some reason, black men. And this is, historically, typical of the workings of capital punishment in real life.
Meanwhile, your rightwing corporate media reported "fact" does not address my assertion: that the deterrent effect of executions, even without its many and serious flaws of assumption etc, does not justify the large risk of allowing one's government to kill its citizens legally and on purpose.
This is what a moral or ethical principle is for - it prevents immediate temptations and shallow fads and passing confusions and emotional storms from persuading one to long term error. It's a bad idea. It always goes wrong. Don't do it.