This review of the criminal deterrence literature focuses on the questions that are largely missing from many recent, excellent, comprehensive reviews of that literature, and from the literature itself. By "missing" I mean, first, questions that criminal deterrence scholars have ignored either completely or to a large extent. These questions range from fundamental (the distributional analysis of the criminal justice system), to those hidden in plain sight (economic analysis of misdemeanors), to those that are well-know yet mostly overlooked (the role of positive incentives, offender's mental state, and celerity of punishment). I also use "missing" to refer to the areas where substantial relevant knowledge exists but is largely disregarded within the criminal deterrence research program. The empirical analysis of environmental and tax compliance are two stark examples. Finally, I stretch "missing" to describe topics that have been both studied and reviewed, but where substantial challenges remain. These include the theoretical explanation for the role of offense history, the proper accounting for the offender's gains, the estimation of the costs of various crimes, and the cost-benefit analysis of crime-reduction policies.