- The Fifth Amendment also bars the government from depriving a person of “life, liberty, or property, without due process of law.” This Due Process clause guarantees criminal defendants a certain amount of procedural fairness. For instance, if Congress were to pass a criminal statute that was unreasonably vague, so that reasonable people could not tell what conduct was forbidden and what was not, a prosecution under that statute would likely violate the Due Process clause.
- The Eighth Amendment prohibits Congress from imposing “cruel and unusual punishments.” For instance, the death penalty for any crime other than murder has effectively been found to be cruel and unusual under the Eighth Amendment.
2. Extension of Bill of Rights to the states: The Bill of Rights applies by its terms only to the federal government, but the Fourteenth Amendment, enacted after the Civil War, imposes limits on what state governments can do. One clause of the Fourteenth Amendment prohibits states from depriving any person of “life, liberty, or property, without due process of law[.]” In the criminal law context, the effect of this Fourteenth Amendment Due Process clause is to make nearly all of the Bill of Rights guarantees applicable to the states.
Example: If a state were to impose the death penalty for petty theft, this would violate the Eighth Amendment ban on cruel and unusual punishments, as made applicable to the states via the Fourteenth Amendment’s due process clause.
B. The “legality” principle: One important limit on the criminal law that has Constitutional underpinnings is the principle of “legality.” Under this principle, a person may not be punished unless his conduct was defined as criminal before he acted. So the legality principle is essentially a rule against “retroactive punishment.”
1. Constitutional underpinnings: The legality principle is not expressly stated anywhere in the Constitution. But several clauses of the Constitution are inspired by the legality principle, i.e., by the idea that retroactive punishment is unfair:
- Art. I, § 9, prohibits Congress from passing any “ bill of attainder,” and Art. I, § 10 prohibits the states from doing so. A bill of attainder is legislation that singles out for punishment a particular individual or easily-identified group.
- Art. I, § 9, also prohibits Congress from passing any “ex post facto” law, and Art. I, § 10, prohibits the states from doing so. An ex post facto law is a law that either makes conduct criminal that was not criminal at the time committed, increases the degree of criminality of conduct beyond what it was at the time it was committed, or increases the maximum permissible punishment for conduct beyond what it was at the time of commission. [Calder v. Bull (1798)]