Source of criminal law. Crimes are classified in terms of their origin as common-law and statutory crimes. Some offences that are defined by statute are merely declaratory of the common law. Each state has its own criminal law, although a general pattern among the states may be observed.

(b) Seriousness of offence. Crimes are classified in terms of their seriousness as treason, felonies and misdemeanors. Treason is defined by the Constitution of the United States, which states that “Treason against the United States shall consist only in levying War against them, or in adhering to their Enemies, giving them Aid and Comfort”.

Felonies include the other more serious crimes, such as arson, homicide, and robbery, which are punishable by confinement in prison or by death. Crimes not classified as treason or felonies are misdemeanors. Reckless driving, weighing and measuring goods with scales and measuring devices that have not been inspected and disturbing the peace by illegal picketing are generally classified as misdemeanors. An act may be a felony in one state and a misdemeanor in another.