It is the prevalent legal system in Continental Europe, Latin America, African countries not formerly under British rule, East Asia (except Hong Kong), Indochina, Thailand, and Indonesia.
Countries using common law, including the United States, may use an inquisitorial system for summary hearings in the case of misdemeanors or infractions, such as minor traffic violations.
In an inquisitorial system, the trial judges (mostly plural in serious crimes) are inquisitors who actively participate in fact-finding public inquiry by questioning defense lawyers, prosecutors, and witnesses.
In an adversarial system, judges focus on the issues of law and procedure and act as a referee in the contest between the defense and the prosecution.
In some United States jurisdictions, it is common practice for jurors to submit questions to the court that they believe were not resolved in direct or cross-examination.
Appeals on the basis of factual issues, such as sufficiency of the sum total of evidence that was properly admitted, are subject to a standard of review that is in most jurisdictions deferential to the judgment of the fact-finder at trial, be that a judge or a jury.
In some adversarial jurisdictions (e.g., the United States, and England and Wales), a prosecutor cannot appeal a "not guilty" verdict (absent corruption or gross malfeasance by the court).
Under the new processus per inquisitionem (inquisitional procedure), an ecclesiastical magistrate no longer required a formal accusation to summon and try a defendant.
As a result, in parts of continental Europe, the ecclesiastical courts operating under the inquisitional procedure became the dominant method by which disputes were adjudicated.
In 1215 this principle became enshrined as article 38 of the Magna Carta: "No bailiff for the future shall, upon his own unsupported complaint, put anyone to his law, without credible witnesses brought for this purposes."
The adoption of the Constitutio Criminalis Carolina (peinliche Gerichtsordnung of Charles V) in 1532 made inquisitional procedures empirical law.
As a member of the judiciary, they are independent and outside the province of the executive branch, and therefore separate from the Office of Public Prosecutions, which is supervised by the Minister of Justice.
Despite high media attention and frequent portrayals in TV series, examining judges are active in a small minority of cases.
[5] The vast majority of cases are therefore investigated directly by law enforcement agencies (police, gendarmerie) under the supervision of the Office of Public Prosecutions (procureurs).
The scope of the inquiry is limited by the mandate given by the prosecutor's office: the examining judge cannot open a criminal investigation sua sponte.
Certain administrative proceedings within some common-law jurisdictions in the United States may be similar to their civil law counterparts but are conducted on a more inquisitorial model.
These types of tribunals or boards function as an expedited form of justice, in which the state agents conduct an initial investigation and the adjudicator's job is to confirm these preliminary findings through a simplified form of procedure that grants some basic amount of due process or fundamental justice.