The Model Penal Code is among the most successful academic law reform projects ever attempted. In the first two decades after its completion in 1962, more than two-thirds of the states undertook to enact new codifications of their criminal law, and virtually all of those used the Model Penal Code as a starting point. The Model Penal Code was influential in a variety of different ways. First, the very notion of a systematic codification of criminal law received a dramatic boost from the Model Penal Code. Apart from the degree to which any particular state recodification resembled the Model Penal Code, the Code provided the impetus for undertaking new codifications in the first place, where many jurisdictions had previously been content with relatively loosely organized compilations of the accumulated criminal statutes passed over the years, many of which simply embodied or assumed traditional common law rules. Second, the specific form of codification developed in the Model Penal Code was powerfully influential. The new state codes typically followed the Model Penal Code's strategy of beginning with sections that combined definitional functions with presumptive rules addressing the "general part" of the criminal law, followed by specific statutes defining particular crimes. Third, the particular resolutions for specific traditional criminal law issues adopted by the Model Penal Code were often quite influential. Although some of the Code's formulations (e.g., the modified felony-murder "presumption") found few followers, many others were broadly adopted either in state codes (e.g., the definitions of mental culpability terms), in judicial elaboration of common law standards or non-Code statutes (e.g., the widespread use of the "substantial step" test in federal court definitions of attempt) or even in constitutional law (e.g., the Supreme Court's near-incorporation of the Model Penal Code standard for use of deadly force in making an arrest into the Fourth Amendment definition of a "reasonable" seizure of the person).
Gerard E. Lynch,
Towards A Model Penal Code, Second (Federal?): The Challenge of the Special Part,
Buff. L. Rev.
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