Substantive versus Procedural Criminal Law

Abstract There are two very important, and very distinct, areas of criminal law: substantive law and procedural law. This entry introduces the reader to the basic differences between the two by exploring a few examples drawn from each. The basic difference between substantive law and procedural law is the question they answer. Substantive law answers the question “What?” It defines which behaviors are criminal and what prosecutors must prove to convict a defendant of a given crime. On the other hand, procedural law answers the question “How?” It sets limits on how police may conduct investigations and on how prosecutors may prove the substantive elements of the case.