As a general rule, the studies finding for deterrence are more credible than their critics (3) but, even if equal, what remains are two options 1) studies finding for deterrence and 2) critics who cannot and do not negate deterrence.
There is no doubt.
"(death penalty city) Henderson, Nev., takes the No. 2 spot in America's Safest Cities despite its location within the Metropolitan Statistical Area of death penalty Las Vegas-Paradise, which ranked ninth this year on Forbes’ list of America’s Most Dangerous Cities." (5)
Everyone is aware.
1) OF COURSE THE DEATH PENALTY DETERS: A review of the debate
MURDERERS MUCH PREFER LIFE OVER EXECUTION
99.7% of murderers tell us "Give me life, not execution"
5) "America's Safest Cities", Lifestyle section, Forbes, 12/15/2011,
Top 25 Most Dangerous Neighborhoods in America, NeighborhoodScout