3.5. Sources of Law: Administrative Law, Common Law, Case Law 
and Court Rules 
LORE RUTZ-BURRI 
 Administrative Law—Agency-Made Law 
State and federal legislatures cannot keep up with the task of enacting legislation on all the myriad 
subjects that must be regulated by law. In each branch of government, various administrative agencies exist 
with authority to create administrative law. At the federal level, for example, the Environmental Protection 
Agency enacts regulations against environmental crimes. At the state level, the Department of Motor 
Vehicles enacts laws concerning drivers’ license suspension. Administrative regulations are enforceable by 
the courts provided that the agency has acted within the scope of its delegated authority from the legislature. 
Common Law 
One important source of criminal law in the United States is common law.  English law developed over 
centuries and, generally, when we refer to American common law, we are referring to the common law rules 
brought over from England to the United States when we became a nation. However, this is not necessarily 
always clear. 
1 LaFave describes the process by which common law was derived in England. 
 “. . . Although there were some early criminal statutes [in England], in the main the criminal law was 
originally common law. Thus by the 1600s the judges, not the legislature, had created and defined the 
felonies of murder, suicide, manslaughter, burglary, arson, robbery, larceny rape, sodomy and mayhem; and 
such misdemeanors as assault, battery, false imprisonment, libel, perjury, and intimidation of jurors. During 
the period from 1660 . . . to 1860 the process continued with the judges creating new crimes when the 
need arose and punishing those who committed them: blasphemy (1676), conspiracy (1664), sedition (18th 
century), forgery (1727), attempt (1784), solicitation (1801). From time to time the judges, when creating 
new misdemeanors, spoke of the court’s power to declare criminal any conduct tending to “outrage decency” 
or “corrupt public morals.” or to punish conduct contra bonos mores:  thus they found running naked in the 
streets, publishing an obscene book, and grave-snatching to be common law crimes. 
Of course, sometimes the courts refused to denote as criminal some forms of anti-social conduct. At times 
their refusal seemed irrational, causing the legislature to step in and enact a statute:  thus false pretenses, 
embezzlement, incest and other matters became statutory crimes in England. … Some immoral conduct, 
mostly of a sexual nature (such as private acts of adultery or fornication, and seduction without conspiracy) 
1. Kerper, H. B. (1979). Introduction to the criminal justice system (2nd ed., pp. 27). West Publishing Company. 
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