This paper examines the deterrent effect of the celerity of the death penalty on homicide rates. Although in recent years there have been a number of investigations of the certainty of execution and deterrence, the effect of celerity of execution has not been examined empirically. As a result, we can only speculate about the merit of the deterrence hypothesis for the celerity of executions, and how previous deterrence and death penalty investigations may be biased due to celerity being ignored. The deterrent effect of the certainty and celerity of the death penalty on homicide rates is examined cross-sectionally for states. Multiple measures of execution and homicide rates are considered, along with various socio-demographic variables in investigating the possible spuriousness of the findings. Analysis consistently fails to provide support for the deterrence argument for the certainty and celerity of executions. Rather, the results fall well within the pattern of negative findings of over five decades of deterrence and death penalty research in the United States.