What is the Difference Between Criminal Law and Criminal Procedure?

Criminal law defines crimes and punishments. Criminal procedure defines individual rights by providing the rules of how investigations, arrests, and trials are carried out.

Introduction

Criminal law and criminal procedure are part of our daily lives, even when we do not interact directly with

the police or courts. We go about our days trusting that criminal laws will help to deter crime and improve our safety. We also trust that our security and individual rights will be protected by criminal procedure. A person who is accused of a crime can expect to have the right to a fair and speedy trial, access to an attorney, the right to remain silent, and more. Both criminal law and criminal procedure connect to the value we place on our freedom and privacy—and the checks we place on the government’s power to take those things away.

Although they are interlinked, criminal law and criminal procedure differ significantly. Each has a different aim and focus. Criminal law focuses on defining crimes, their elements, and punishments. Criminal procedure focuses on defining the rules for the legal process so that individual rights can be protected. Procedure regulates every step: from investigation to search, arrest, interrogation, trial, and sentencing. Read on to learn more about the distinctions between—and equal importance of—criminal law and criminal procedure. 

What Is Criminal Law? 

Criminal law is a type of substantive law. Substantive law is the body of law that creates and defines duties, rights, punishments, and more. The sources of substantive criminal law include common law, the Constitution (federal and state versions), statutes, and case law. Statutes are laws passed by the government. Examples include federal statutes such as the United States Code and state statutes such as the California Penal Code. Both federal and state criminal laws look to the Model Penal Code as a guiding framework. On a local level, there are even city or municipal codes to define crimes. 

These sources of substantive law can answer key criminal law questions. For example: jury instructions tell us what the elements are, and statute or common law define the offense. As a sample, consider the California Penal Code Section 187 (a statute) which defines the offense of murder in California. The elements of the murder charge are found in the jury instruction CALCRIM No. 520. 

Criminal Procedure

Criminal procedure is a type of procedural law. Procedural law enforces the duties, rights, and punishments created by substantive law.

Sources of criminal procedure include the U.S. Constitution, Criminal Rules of Procedure, Rules of Evidence, and Sentencing Guidelines.

The sources can also answer key criminal procedure questions. For example:

In sum, criminal law and criminal procedure draw from similar sources to meet different goals. Criminal law focuses on creating definitions that the public can rely on. Criminal procedure focuses on regulating a standardized process to enforce equal protection. 

Conclusion

Perhaps you used to loop together criminal law and criminal procedure. Now you know the key ways that they differ, and why this distinction is important to all. However, this is a broad overview, and there is always more to learn. Should you have any questions, don’t hesitate to reach out.