Even after executions resumed, homicide rates appeared unaffected, the analysis found. The Times also looked at contiguous and demographically similar states, and found no pattern that differentiated death penalty states from those without capital punishment. Massachusetts and Rhode Island, with no death penalty, had homicide rates of 3.7 per 100,000 and 4.2 per 100,000, respectively, from 1977 to 1997, while Connecticut, a death penalty state, had a rate of 4.9 per 100,000. The survey by The Times is similar to the type of analysis criminologists used in the years before the Supreme Court's Furman decision to conclude that state homicide rates were not affected by death penalty laws. The review by The Times confirms that those patterns appear to continue under the new era of capital punishment statutes.
Some researchers still contend that the death penalty has a measurable deterrent effect.
He said that if variations like unemployment, income inequality, likelihood of apprehension and willingness to use the death penalty are accounted for, the death penalty shows a significant deterring effect. Most criminologists, however, discount Professor Ehrlich's work.