Criminal offenses are classified according to their seriousness. For crimes against property, the gravity of a crime is generally commensurate with the value of the property taken or damaged: the greater the property value, the more serious the crime. For crimes against persons, the same proportionality principle applies to bodily injury inflicted upon individuals: the greater the injury, the more serious the crime. However, a host of other factors can influence the seriousness of a criminal offense. These factors include whether the defendant had a prior criminal record; whether the defendant committed the crime with cruelty, malice, intent, or in reckless disregard of another person's safety; and whether the victim was a member of a protected class (e.g., minors, minorities, senior citizens, the handicapped, etc.). Thus, a less serious crime can be made more serious by the presence of these additional factors, and a more serious crime can be made less serious by their absence.
Three categories of criminal offenses were known at common law, treason, felony, and misdemeanor, with treason being the most serious type of crime and misdemeanor being the least serious. The common law distinction between treason and felony was particularly important in England because a traitor's lands were forfeited to the Crown. Under a doctrine known as "corruption of the blood," the traitor also lost the right to inherit property from relatives, while the relatives lost the right to inherit from the traitor. U. S. law has never endorsed corruption of the blood as a criminal penalty, and so treason was dropped as a separate classification of crime in the colonies.
Today every U. S. jurisdiction retains the distinction between felony level criminal offenses and misdemeanor level offenses. However, most jurisdictions have added a third-tier of criminal offense, typically called an infraction or a petty offense. Although the definitions of all three classes differ from one jurisdiction to the next, they do share some common characteristics.
Felonies, Misdemeanors, and Infractions
The power to define a crime and classify it as a felony, misdemeanor, or infraction rests solely with the legislature at the federal level (see U. S. v. Hudson, 7 Cranch 32, 11 U.S. 32, 3 L.Ed. 259 [U. S. 1812]). Federal courts do not have the power to punish any act that is not forbidden by federal statute. Most crimes made punishable by federal law are set forth in Title 18 U.S.C. sections 1 et seq.
In the eighteenth century U. S. courts possessed the power to define crimes and establish classifications for criminal offenses. These judicially-created offenses were known as common law crimes. By the early nineteenth century, federal common law crimes were under increasing attack as violating the mandate of the separation of powers established by the U. S. Constitution. Article I of the Constitution gives Congress the power to make law, while Article III gives the judiciary the power to interpret and apply it. Thus, the constitutionally limited role of federal courts precludes them from defining crimes or creating classifications for criminal offenses.
Most states have also abolished common law crimes. In these states the legislature is given the primary and often sole responsibility for defining illegal behavior (the executive branch in a few states plays a limited lawmaking function via executive orders and administrative agency rules and regulations). In the minority of states that still recognize common law crimes, judges generally are not permitted to create new common law crimes from the bench. Instead, all 50 states and the District of Columbia rely on their penal code to shape the nature and scope of their jurisdiction's criminal laws, and when a penal code designates an offense as a felony, misdemeanor, or infraction, that designation is normally deemed conclusive by the courts.