Co-Investigating Judges

The Co-Investigating Judges investigates facts sets out in Introductory and Supplementary Submissions from the Co-Prosecutors. After the investigation has been concluded the Co-Investigating Judges will issue a Closing Order containing an indictment with an order to send the case for trial, or a dismissal order terminating the proceedings  (more details below).

There are two Co-Investigating Judges:
Mr. You Bunleng (Cambodia)
Mr. Siegfried Blunk (Germany)

Characteristics of proceedings before the ECCC and of the Co-Investigationg Judges' functions:

There are major differences between the applicable procedure before the ECCC, especially concerning the investigative stage, and the applicable procedure before the other International Tribunals, which draws its inspiration from common law systems. In fact, following the example of cambodian law which welcomed the french concept of investigating judge, the investigations before the trial stage are carried out not by the Parties (Prosecutors and Defense), but by two Co-Investigating Judges, a national Judge and an international Judge. 

They play a specific role in the ECCC since they are responsible for collecting evidence with a view to determine, on the one hand, if the facts set out by the Co-Prosecutors in the Introductory Submission constitute a crime within the jurisdiction of the ECCC and, on the other hand, if the charged person is to be indicted and sent to trial before the Trial Chamber. Furthermore, unlike common law systems where the evidence is presented directly to the Judge by the Parties, at the ECCC all the documents collected during the investigation and placed in the case file by the OCIJ will constitute the basis for the proceedings before the Trial Chamber.


Principles in accordance to which the Office of the Co-Investigating Judges must act:

  • Impartiality: the Co-Investigating Judges shall investigate impartially, whether the evidence is inculpatory or exculpatory;
  • Independence: the Co-Investigating Judges must act independently, meaning that they shall not accept or seek any instructions from any government or any other source;
  • Equality of arms: the Co-Investigating Judges shall always strike a balance between the rights of the different Parties, protecting the interests of both victimes and witnesses and respecting the rights of the Defense and the Co-Prosecutors;
  • Confidentiality: proceedings at the investigative stage are in written and, as a general rule, secret. This to protect the rights and interests of the Parties, in particular:  

          - respecting the presumption of innocence of the suspect or the charged person,

          - allowing protective measures for the identity of witnesses and victims, if necessary,
          - conducting an efficient investigation;

For all practical purposes, this means that any subject taking part in the proceedings is bound by confidentiality and,consequently, all documents and informations included in the case file (documents relating to the investigation, charged persons interviews, witnesses and civil parties interviews, research carried out by experts appointed by the Co-Investigating Judges, ect.) are confidential, even in the case where this document is simply including common knowledge. Considering the peculiar nature of the ECCC, the principle of confidentiality is however flexible in order to provide the public with a minimum amount of information. 

The investigative phase

The investigative stage before the ECCC is composed of two phases:

The opening of the investigation

This phase begins with the opening of a preliminary investigation by the Co-Prosecutors, on their own motion or at the request of one of the parties or their lawyers, in a way to, on the one hand, determine if there is evidence showing that crimes within the jurisdiction of the ECCC were committed, on the other hand, identify potential suspects and witnesses. Following this preliminary investigation and if the Co-Priosecutors and in case that the Co-Prosecutors have reasons to believe that crimes within the jurisdiction of the ECCC have been committed, they open a judicial investigation by sending an Introductory Submission, which makes reference to the facts, the type of offences alleged, the applicable law and, should the case arise, to the name of any person to be investigated.

Investigation by the Co-Investigating Judges

Once the Introductory Submission has been filed, the Co-Investigating Judges shall investigate the facts set out in the Introductory Submission. Under no circumstances they shall investigate new facts, unless they have received a Supplementary Submission from the Co-Prosecutors.  The Co-Investigating Judges have the power to charge any person against whom there is clear and consistent evidence indicating that such person may be criminally responsible for the commission of a crime referred to in a Introductory Submission or a Supplementary Submission, even where such persons were not named in the submission. Since this moment, they are under an obligation to investigate impartially, whether the evidence is inculpatory or exculpatory. In fact, they act in the interest of Society and thus they do not serve the interests of the Defense or the Co-Prosecutors. 

In doing this, they may take any investigative action conducive to ascertaining the truth, such as:

  • question Suspects and Charged Persons;
  • interview victims and witnesses;
  • seize physical evidence;
  • seek expert opinions;
  • conduct on-site investigations;
  • issue summonses, Arrest Warrants, Detention Orders and Arrest and Detention Orders;
  • take any appropriate measures to provide for the safety and support of potential witnesses and other sources;
  • seek information and assistancefrom any sources that they deem appropriate (States, the United Nations, intergovernmental or non-governmental organizations).

During the investigation, the parties (Co-Prosecutors, Charged Persons and Civil Parties) may also request the Co-Investigating Judges to make such orders or undertake such investigative actions as they consider necessary for the conduct of the investigation. The Co-Investigating Judges may agree or not with the request, in the latter case they shall issue a reasoned rejection order as soon as possible and, in any event, before the end of the judicial investigation. The order shall be subject to appeal before the Pre-Trial Chamber.

End of the Investigation

Where the Co-Investigating Judges consider that an investigation has been concluded, they shall notify all the parties and their lawyers, whom shall have fifteen days to request further investigative action. Where the Co-Investigating Judges decide to reject such requests, they shall issue a reasoned order, which is subject to appeal before the Pre-Trial Chamber. Once this period has expired, been waived, or the appeals heard by the Pre-Trial Chamber, the Co-Investigating Judges shall forward the case file to the Co-Prosecutors, who shall issue a written final submission where they consider that the investigation has been concluded. In their final submission the Co-Prosecutors may request the Co-Investigating Judges to either indict the Charged Person and send him or her for trial, or to dismiss the case. Nevertheless, the Co-Investigating Judges are not bound by the Co-Prosecutors’ submissions. They shall conclude the investigation by issuing a Closing Order, either indicting the Charged Person and sending him or her to trial, or dismissing the case.

The Co-Investigating Judges shall issue a Dismissal Order if:

  • the acts in question do not amount to crimes within the jurisdiction of the ECCC;
  • the perpetrators of the acts have not been identified;
  • there is no sufficient evidence against the Charged Person. In this case Provisional Detention and Bail Orders are put to an end

On the other hand, the Co-Investigating Judges shall issue an Indictment if there is sufficient evidence against the Charged Person, relating to acts which constitute a crime falling within the jurisdiction of the ECCC. The Indictment sets out the identity of the Accused, a description of the material facts and their legal characterisation, as well as the nature of the criminal responsibility.

The Co-Prosecutors, the Accused and Civil Parties must be notified upon issue of a Closing Order. The Indictment is subject to appeal only by the Co-Prosecutors, while the Dismissal Order is subject to appeal by the Co-Prosecutors and Civil Parties, where the Co-Prosecutors have appealed. Where no appeal is filed against a Closing Order, the Greffier of the Co-Investigating Judges shall forward the case file to the Greffier of the Trial Chamber to allow a date for trial to be set, or to the Office of Administration for archiving, in case a Dismissal Order is issued. From this moment, the Co-Investigating Judges don’t play any further role in the case. On the other hand, when new evidence becomes available after a Dismissal Order comes into force, the judicial investigation may be re-opened by the Co-Investigating Judges at the initiative of the Co-Prosecutors.  The Co-Prosecutors participate in the following proceedings as parties and they present their oral submissions as they consider necessary for justice to be done.