In most states persons accused of violating the law before they are 18 years of age are under the jurisdiction of the juvenile courts, and persons accused of violating the law when they are 18 years of age or older are under the jurisdiction of the criminal courts. Some states begin prosecuting persons as adults in the criminal court system when they are 17 years of age, and some states begin prosecuting persons as adults in the criminal court system when they are 16 years of age.

But all states have transfer laws that permit or require criminal prosecution of some young offenders—even though they are still of juvenile age, as defined by the state’s laws. Transfer laws vary from state to state, but generally fall within three categories: (1) judicial waiver laws that allow juvenile courts to waive jurisdiction on a case-by-case basis; (2) prosecutorial discretion or concurrent jurisdiction laws that define a class of cases that may be brought in juvenile court or in criminal court—usually at the discretion of the prosecutor; and (3) statutory exclusion laws that grant criminal courts exclusive jurisdiction over certain classes of cases involving juvenile-age offenders.

The laws that govern when a person of juvenile age may be prosecuted as an adult in the criminal court system are generally located in a state’s statutes.

In New Jersey, the age of majority for criminal responsibility is 18, meaning that individuals who are 18 or older are typically prosecuted in the criminal courts. However, New Jersey does have transfer laws that allow for the prosecution of juveniles as adults under certain circumstances. These transfer laws include judicial waiver, prosecutorial discretion, and statutory exclusion. Judicial waiver permits juvenile courts to waive their jurisdiction and transfer a juvenile case to adult criminal court based on factors such as the nature and seriousness of the offense, the juvenile's age, and prior record. Prosecutorial discretion allows prosecutors to choose whether to file certain cases against juveniles in adult court. Statutory exclusion laws automatically exclude certain serious offenses from juvenile court jurisdiction, meaning that juveniles charged with these crimes are directly filed in adult court. The specific criteria and procedures for transferring juvenile cases to adult court are detailed in New Jersey's statutes, and the decision to prosecute a juvenile as an adult can have significant implications for the accused, including the potential for harsher sentences and the loss of certain protections afforded to juveniles.