In the mid-1960's, Thorsten Sellin appeared to have successfully demonstrated the inability of the death penalty to affect homicide rates. The issue was reopened in the 1970's, however, by Isaac Ehrlich, who introduced econometric techniques in the measurement of deterrence and suggested that capital punishment may play a deterrent role in the cost-effectiveness considerations of rational potential murderers. Ehrlich's effort was interpreted as having rightist political implications and was rebuked by a spate of subsequent studies. The critiques addressed shortcomings in Ehrlich's data sources and his methodology, concluding once more that the potence of capital punishment to deter murder eludes conclusive proof and remains a highly questionable tenet. In the course of this research, negative correlations have been indicated with some consistency between the incidence of other crimes and the likelihood of being apprehended or sentenced, i.e., the consistency of law enforcement. These methodologies may be applicable to the study of crime forms other than homicide and may prove useful in criminological analyses apart from the capital punishment controversy. Statistical formulas, 95 footnotes, and over 50 references are given.