Morissette v. United States
342 U.S. 246 (1952)

  • Morissette lived near a bombing range. He entered the range, took some shell fragments he found lying around, and sold them as scrap metal.
  • When the Air Force found out what happened, he was arrested and charged with "knowingly converting" government property (18 U.S.C. 641)
    • Morissette argued that he thought that the shell fragments were abandoned property.
  • The Trial Judge instructed the jury that in order to convict they had to find that Morissette intended to take the shells, not that he intended to "knowingly convert" (aka steal) someone else's property.
  • The Trial Court convicted Morissette. He appealed.
  • The Appellate Court affirmed. He appealed.
    • The Appellate Court found that the term "knowing conversion" should have its traditional tort law meaning, simply an intentional exercise of dominion over property that is not one's own.
  • The US Supreme Court reversed.
    • The US Supreme Court found that 641 should be read to require intent as an element, even if it is not explicitly stated in the Statute.
    • The Court found that strict liability has traditionally only be used in very minor offenses (such as parking tickets), and the historical common la has always required intent (aka mens rea) for crimes involving theft.
      • The Court noted that there was no bright line rule for which offenses required mens rea.
  • Basically, this case said that for relatively serious crimes, there must be a mental element on the part of the defendant to commit a crime (aka mens rea). You cannot be found guilty of a crime just because you physically committed the act (aka strict liability)
    • Even though Morissette did take the government property, he wasn't trying to steal it, and he cannot be found guilty.
    • For example, if you are a professional juggler, and you are juggling chain saws, and you drop one and it kills somebody, you won't be guilty of murder because you weren't trying to kill someone.
    • On the other hand, for minor infractions such as parking tickets, you can be found guilty even if you honestly thought you were parked legally.