Execution moratoriums, commutations and deterrence: the case of Illinois

In an earlier work the impact of an execution moratorium in Texas on the monthly returns (first differences) of homicides was investigated. That moratorium was judicially imposed pending the appeal of a death sentence that could have had widespread consequences. A similar methodology is applied to the state of Illinois. In January 2000, the Governor of Illinois declared a moratorium on executions pending a review of the judicial process that condemned certain murderers to the death penalty. In January 2003 just prior to leaving office, the Governor commuted the death sentences of all of those who then occupied death row. It is found that these actions are coincident with the increased risk of homicide incurred by the residents of Illinois over the 48 month post-event period for which data were available. The increased risk produced an estimated 150 additional homicides during the post-event period.