Model Penal Code

The Model Penal Code (MPC) is a text which was developed by the American Law Institute (ALI) in 1962. The chief reporter on the project was Herbert Wechsler, and contributors included Sanford Kadish and numerous other noted criminal law scholars. The current form of the MPC was last updated in 1981. The purpose of the MPC was to stimulate and assist legislatures in making an effort to update and standardize the penal law of the United States of America. Primary responsibility for criminal law lies with the individual states, and such national efforts work to produce similar laws in different jurisdictions. The standard they used to make a sense of what the penal code should be was one of "contemporary reasoned judgment" — meaning what a reasoned person at the time of the development of the MPC would judge the penal law to do. The ALI performed an examination of the penal system in the USA and the prohibitions, sanctions, excuses, and authority that are used throughout. The MPC was a combination of what the ALI deemed to be the best rules for the penal system in the United States. Since its formulation, the MPC has played an important role in standardizing the codified penal laws of the United States.

Under the MPC, crimes are defined in terms of a set of "elements of the offense," each of which must be proven to the finder of fact beyond a reasonable doubt. There are three types of elements:

The elements are those facts that:

All but the last two categories are material elements, and the prosecution must prove that the defendant had the required kind of culpability with respect to that element.

One of the major innovations of the MPC is its use of standardized mens rea terms (criminal mind, or in MPC terms, culpability) to determine levels of mental states, just as homicide is considered more severe if done intentionally rather than accidentally. These terms are (in descending order) "purposely", "knowingly," "recklessly", and "negligently", with a fifth state of "strict liability", which is highly disfavored. Each material element of every crime has an associated culpability state that the prosecution must prove beyond a reasonable doubt.

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