The Difference Between Procedural Law and Substantive Law

Working Together to Deliver Justice While Protecting Individual Rights

A typical US courtroom as viewed from behind the witness stand.
A Typical US Courtroom Ready for Trial. Getty Images Pool Photo

Procedural law and substantive law are the two primary categories of law in the dual U.S. court system. These two types of law play different but essential roles in protecting the rights of individuals in the United States criminal justice system.

Key Terms

  • Procedural law is the set of rules by which courts in the United States decide the outcomes of all criminal, civil, and administrative cases. 
  • Substantive law describes how people are expected to behave according to accepted social norms. 
  • Procedural laws govern how court proceedings dealing with the enforcement of substantive laws are conducted. 

Two Categories of Law

Substantive law — literally the “substance” of the law — governs how people are expected to behave according to accepted social norms. The Ten Commandments, for example, is a set of substantive laws. Today, substantive law defines rights and responsibilities in all court proceedings. In criminal cases, substantive law governs how guilt or innocence is to be determined, and how crimes are charged and punished.

Procedural laws govern how court proceedings that deal with the enforcement of substantive laws are conducted. Since the primary object of all court proceedings is to determine the truth according to the best available evidence, procedural laws of evidence govern the admissibility of evidence and the presentation and testimony of witnesses. For example, when judges sustain or overrule objections raised by lawyers, they do so according to procedural laws.

Both procedural and substantive law may be altered over time by Supreme Court rulings and constitutional interpretations.

Application of Criminal Procedural Law

While each state has adopted its own set of procedural laws, usually called a “Code of Criminal Procedure,” the basic procedures followed in most jurisdictions include:

  • All arrests must be based on probable cause;
  • Prosecutors file charges that must clearly spell out what crimes the accused person allegedly committed;
  • The accused person is arraigned before a judge and given the opportunity to enter a plea — a statement of guilt or innocence;
  • The judge asks the accused whether they need a court-appointed attorney or will supply their own attorney;
  • The judge will either grant or deny the accused bail or bond and set an amount to be paid;
  • An official notice to appear in court is delivered to the accused;
  • If the accused and prosecutors cannot reach a plea bargain agreement, trial dates are set;
  • If the accused person is convicted at trial, the judge advises them of their rights to appeal;
  • In the case of guilty verdicts, the trial moves to the sentencing phase.

In most states, the same laws that define criminal offenses also set the maximum sentences that can be imposed, from fines to time in jail. However, the state and federal courts follow very different procedural laws for sentencing.

Sentencing In State Courts

The procedural laws of some states provide for a bifurcated or two-part trial system, in which sentencing is conducted in a separate trial held after a guilty verdict has been reached. The sentencing phase trial follows the same basic procedural laws as the guilt or innocence phase, with the same jury hearing evidence and determining sentences. The judge will advise the jury of the range of severity of sentences that may be imposed under state law.

Sentencing In Federal Courts

In the federal courts, judges themselves impose sentences based on a more narrow set of federal sentencing guidelines. In determining an appropriate sentence’ the judge, rather than a jury, will consider a report on the defendant’s criminal history prepared by a federal probation officer, as well as evidence presented during the trial. In the federal criminal courts, judges use a point system based on the defendant’s prior convictions, if any, in applying the federal sentencing guidelines. In addition, federal judges do not have the leeway to impose sentences more or less severe than those allowed under the federal sentencing guidelines.

Sources of Procedural Laws

Procedural law is established by each individual jurisdiction. Both the state and federal courts have created their own sets of procedures. In addition, county and municipal courts may have specific procedures that must that must be followed. These procedures typically include how cases are filed with the court, how parties involved are notified, and how official records of court proceedings are handled.

In most jurisdictions, procedural laws are found in publications such as the “Rules of Civil Procedure,” and “Rules of Court.” The procedural laws of the federal courts can be found in the “Federal Rules of Civil Procedure.”

Basic Elements of Substantive Criminal Law

In comparison to procedural criminal law, substantive criminal law involves the “substance” of the charges filed against accused persons. Every charge is made up of elements, or the specific acts required to amount to the commission of a crime. Substantive law requires that prosecutors prove beyond all reasonable doubt that every element of crime took place as charged in order for the accused person to be convicted of that crime. For example, to secure a conviction for a charge of felony-level driving while intoxicated, prosecutors must prove the following substantive elements of the crime:

  • The accused person was, in fact, the person operating the motor vehicle;
  • The vehicle was being operated on a public roadway;
  • The accused person was legally intoxicated while operating the vehicle; and
  • The accused person had prior convictions for driving while intoxicated.

Other substantive state laws involved in the above example include:

  • The maximum allowed percentage of alcohol in the accused person’s blood at the time of arrest; and
  • The number of prior convictions for driving while intoxicated.

Because both procedural and substantive laws can vary by state and sometimes by county, persons charged with crimes should consult with a certified criminal law attorney practicing in their jurisdiction.

Sources of Substantive Law

In the United States, substantive law comes from the state legislatures and Common Law — law based on societal customs and enforced by the courts. Historically, Common Law made up set of statutes and case law that governed England and the American colonies prior to the American Revolution.

During the 20th century, substantive laws changed and grew in number quickly as Congress and the state legislatures moved to unify and modernize many principles of Common Law. For example, since its enactment in 1952, the Uniform Commercial Code (UCC), governing commercial transactions has been fully or partially adopted by all U.S. states to replace the Common Law and differing state laws as the single authoritative source of substantive commercial law.