nThe United States Constitution limits the power of Congress and the state legislatures to enact criminal statutes.
nArticle III, Section 3 provides that the crime of treason against
the United States “shall consist only
in levying War against them, or in adhering to their Enemies, giving them Aid and Comfort.”
nOther constitutional limitations on the criminal law include the prohibitions against bills of attainder and ex post facto laws contained in Article I, Sections 9 and 10 and many of the provisions of the Bill of Rights.