Each of the following sections will overview the origins of the current U.S. law. Exploring how past legal systems came together to constitute a uniquely American legal system.

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 the 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 driver’s 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 it became a nation. It is important to note that there are no federal common law crimes. If Congress has not enacted legislation to make certain conduct criminal, that conduct cannot constitute a federal crime.

The most straightforward definition of common law is that it’s a “body of law” based on court decisions rather than codes or statutes. But what is the history of common law, and why is it so important in the United States legal System? Watch the following video on Common Law [Streaming Video] to find out.

Judge-Made Law: Case Law

The term case law refers to legal rules announced in opinions written by appellate judges when deciding appellate cases before them. Judicial decisions reflect the court’s interpretation of constitutions, statutes, common law, or administrative regulations. When the court interprets a statute, the statute, as well as its interpretation, controls how the law will be enforced and applied in the future. The same is true when a court interprets federal and state constitutions. When deciding cases and interpreting the law, judges are bound by precedent.

Stare Decisis and Precedent (Example)

The doctrine of stare decisis comes from a Latin phrase that states, “to stand by the decisions and not disturb settled points.” It tells the court that if the decisions in the past have held that a rule governs a certain fact situation, that rule should govern all later cases presenting the same fact situation. Stare decisis permits society to presume that bedrock principles are founded in the law rather than in the proclivities of individuals, and thereby contribute to the integrity of our constitutional system of government, both in appearance and fact” (Vasquez v. Hillery, 474 U.S. 254, 1986).

Let’s imagine a family where the parents initially set a curfew of 10:00 p.m. for their oldest child when they were a teenager. Now, as the younger sibling enters their teenage years, the parents are considering a different curfew, perhaps 9:00 p.m. However, to maintain fairness and consistency, they decide to keep the same curfew of 10:00 p.m. for the younger sibling as well.

This scenario underscores the legal concepts of precedent and stare decisis. Precedent involves using past decisions as examples for current ones. In this situation, the parents are looking back at what they decided for the older sibling (the precedent) and choosing to apply the same rule to the younger sibling, even though they might have initially considered a different curfew time.

Stare decisis, which means “to stand by things decided,” supports the idea that once a decision has been made in the past (a precedent), it should generally be followed in similar future cases. In this family context, maintaining the same curfew for both siblings helps ensure fairness. It prevents the appearance of favoritism or inconsistency in the rules applied to different family members.

By keeping the curfew consistent, the parents are demonstrating a commitment to fairness and the principle that matters should generally stay decided. This concept is vital in legal systems as well, where adhering to precedent and stare decisis helps establish a sense of predictability and fairness in the application of rules and laws.

Court Rules of Procedure

The U.S. Supreme Court and state supreme courts play a crucial role in shaping laws that regulate the procedures followed in the lower courts within their jurisdiction. These rules are essential as they often provide significant rights for the defendant. Take, for instance, the rules governing speedy trials, a fundamental right protected by the Constitution. While the Constitution outlines the overarching principle, the specific implementations are guided by the court rules in each jurisdiction.

For example, a state supreme court might establish rules to ensure that criminal defendants have a right to a trial within a certain timeframe. Furthermore, local courts can contribute to this legal framework by passing their own set of rules that govern the day-to-day practice of law within their jurisdiction. As an illustration, a local court rule may specify the procedures and deadlines for filing cases, creating a standardized and efficient process for handling legal matters in that particular area. In this way, the collaboration between higher courts, like the U.S. Supreme Court and state supreme courts, alongside local courts, ensures a comprehensive legal structure that balances constitutional principles with practical considerations at both national and local levels.

Licenses and Attributions for Sources of Law: Administrative Law, Common Law, Case Law, and Court Rules

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“Sources of Law: Administrative Law, Common Law, Case Law, and Court Rules” is adapted from “3.5. Sources of Law: Administrative Law, Common Law, Case Law and Court Rules” by Lore Rutz-Burri in SOU-CCJ230 Introduction to the American Criminal Justice System by Alison S. Burke, David Carter, Brian Fedorek, Tiffany Morey, Lore Rutz-Burri, and Shanell Sanchez, licensed under CC BY-NC-SA 4.0. Modifications by Sam Arungwa, revisions by Roxie Supplee, licensed CC BY-NC-SA 4.0, include substantially rewriting.