Key Principles of Criminal Procedure and Trial Rights

Principles of Criminal Procedure

Principle of legality: This principle permeates the entire criminal procedure. Everyone is entitled to know beforehand what conduct is criminal, who may go to court, who initiates the proceeding, and who concludes any action. Any action in the judicial process must be carried out according to the forms and requirements established by law.

Presumption of Innocence

Principle of presumption of innocence: Every person is presumed innocent until a trial judge decides otherwise by a reasoned decision based on clear and sufficient evidence of guilt.

Duality and Equality of Arms

Principle of duality and equality of arms: There must be two parties—an accuser and a defender—and both must be procedurally equal. Effective equality arises especially in the trial phase, where each side has equal rights to plead and to present and challenge evidence.

Principle of Contradiction

Principle of contradiction: No one can be condemned without a trial. The trial phase guarantees protection of the accused, including the right to be informed of the charges, to confront evidence, and to respond to allegations.

Impartiality

Principle of impartiality: Cases must be resolved by an impartial judge. Except in some limited cases, the investigating judge should not be the same judge who decides the merits, so as not to be contaminated by information arising from the investigation.

Principles of the Pretrial Stage

Inquisitorial aspects: The pretrial phase involves investigation and prosecution of crimes and the identification of a person as a possible perpetrator of the offense.

Official initiation of proceedings: Authorities should initiate proceedings or bring matters before a court to determine whether criminal conduct occurred. Certain circumstances—such as valid waivers, transactions between parties, or particular procedural acts—may affect or impede continuation of the proceedings.

Principle of secrecy of proceedings: Pretrial actions are usually secret and known only to the parties and authorized authorities. The judge may order secrecy to protect the investigation, victims, witnesses, or the integrity of the process.

Principles of the Trial Stage

Adversarial Principle

Adversarial principle: The judge's mission is to hear the charges against a person. Prosecution and defense advocate on behalf of their positions. Evidence must be admitted according to the rules and produced in the appropriate forums; the opening of the trial is typically made in a public hearing by the prosecution or at its request.

Publicity

Publicity principle: Proceedings are witnessed by the parties and by society. Publicity protects the administration of justice from being removed from public scrutiny and helps maintain public confidence in the courts. Closed or private hearings, where only the parties are present, are exceptions that must be justified by a reasoned and specific order.

Oral Procedure, Immediacy, and Concentration

Oral criminal procedure: Criminal trials should be eminently oral. The judge must have direct contact with the prosecution, defense, witnesses, and the evidence presented.

Principle of immediacy: The judge should attend the taking of evidence, personally observing testimony and other evidence directly, without intermediaries, so as to appreciate credibility and relevance.

Concentration principle: The trial should be developed in a concentrated manner, ideally in a single session on the same day. If that is not possible, sessions should be scheduled on successive nearby days to preserve continuity and the integrity of proceedings.

Summary of Core Concepts

• Legality: actions follow the law.
• Presumption of innocence: proof is required for conviction.
• Equality of arms: procedural parity between parties.
• Contradiction and adversity: right to confront and respond.
• Impartiality: decisions by unbiased judges.
• Secrecy and publicity: balance between confidentiality and public control.
• Orality, immediacy, concentration: practical rules to ensure fair and effective trials.

These principles operate together throughout the pretrial and trial stages to protect procedural fairness, the rights of the accused, victims, and public confidence in the justice system.