Capital punishment attracts strong and opposing moral positions: execution by the state under any condition is wrong versus execution as just retribution for heinous killing. In this book, the author rejects these moral arguments as a basis for determining the social value of the death penalty and considers the issue scientifically by determining whether capital punishment deters willful killing. Using evidence from legal history, the impairment / abolishment of the death penalty between 1968 and 1976 and the right of states to adopt or abolish the death penalty, this book examines the statistical relationship between the death penalty and deterrence. The investigation considers the murder rate during periods with and without the threat of capital punishment, the role of state commitment to its own capital punishment system, and fairness in administering the death penalty.