The role of expert witnesses

Mr. Philip Short, who appeared before the Trial Chamber during four days of hearings this this week, is one of several experts who have provided expert testimony in Case 001 and Case 002/01.

The Internal Rules of the ECCC allow the Trial Chamber to seek expert opinion on any subject deemed necessary to the proceedings (Internal Rule Rule 31 (1) ).  An expert shall be appointed through a judicial order, which specifies his/her exact assignment. ((Internal Rule Rule 31 (3) ). 

The Trial Chamber has further elaborated on the roles of experts as follows*:

“Other hybrid and international tribunals have considered as experts individuals possessing relevant skill or specialised knowledge acquired through education, experience or training in the proposed field of expertise.. The mere fact that an expert witness has a previous association with an external organization does not disqualify him or her from being called as an expert. Under the ECCC legal framework, all experts are appointed by the Chamber to ensure independence. Experts are obliged to testify with the utmost neutrality and objectivity, and challenges regarding bias of a witness called as an expert are a matter related to the evaluation of the evidence given by him and not its admissibility. In determining whether an individual possesses sufficient credentials to be called as an expert, a Chamber may have recourse to the individual's curriculum vitae, articles, publications or other information relating to him or her relevant to the subject on which expertise is required, including the proposed expert's former and present positions.

According to the international jurisprudence, the role of expert witnesses is to enlighten the Chamber on specific issues of a technical nature, requiring special knowledge in a specific field. They provide clarification, context, or additional assistance for the purpose of a Chamber's assessment of evidence, but do not testify on disputed facts as would fact witnesses. Expert witnesses may not express opinions on ultimate issues of fact, as only the Chamber is competent to make a judicial determination on the issues in the case. Fact  witnesses, on the other hand, testify about the crimes with which an Accused charged, but may express opinions only in so far as they emanate from personal experience. Their testimony is limited to what they personally saw, heard or experienced”.

Certain expert witnesses may also have knowledge of facts being adjudicated. In the case of Philip Short, the Trial Chamber decided that, as he was principally sought by parties due though his personal knowledge of facts relevant to Democratic Kampuchea through interviews with leaders and cadres, he could also be questioned on facts within his personal knowledge relevant to Case 002/01.

Other expert witnesses in Case 002/01 during trial:
Professor David Chandler

Medical experts who testified about the health condition of the Accused:
Dr. Seena Fazel
Professor John Campbell
Dr. Lim Sivutha


Case 001 expert witnesses during trial:
Dr. Chhim Sotheara was called to testify as an expert on the psychological impact of the Khmer Rouge regime.

Professor Craig Etcheson was called as an expert to testify on the implementation of the Communist Party of Kampuchea’s (CPK) policy.

Professor David Chandler was called as an expert to testify on the functioning of S-21.

Professor Ka Sunbaunat and Dr. Françoise Sironi-Guilbaud was called as an expert to present a psychological assessment of the Accused conducted in 2008 with an update in August 2009.

Former correspondent Mr. Nayan Chanda testified as an expert on the issue of armed conflict, focusing on the Cambodian-Vietnamese conflict during the Khmer Rouge regime.

Raoul Marc Jennar was called to testify as an expert on issues relating to practical and theoretical foundations and operations of the Democratic Kampuchea (DK) regime of terror.

Justice Richard Goldstone was called as an expert to testify on issues relating to guilty pleas in international criminal tribunals.

Stéphane Hessel was called in order to contribute as an expert on the issue of forgiveness.


* Decision on assignment of experts, E215,  5 July 2012 para 15-16

Protective measures in the ECCC proceedings

When a witness, civil party or complainant requests protection measures or informs an officer of the court that they have security or confidentiality concerns, they are referred to the  ECCC's Witness and Expert Support Unit (WESU). 

There are many ways a person can inform the ECCC that they have a concern.  A civil party or a complainant might make a note on their official application form, or they may inform the ECCC’s Victims Support Section (VSS) or, for civil parties, their civil party lawyer.  A witness, civil party or complainant may be interviewed by an officer from the Office of the Co-Investigating Judges and they may inform the investigators conducting the interview, or they may tell the Judges themselves.  However, if a person informs the ECCC that they have concerns they will always be directed to WESU.

When WESU learns that a Civil Party or witnesses has concerns about security or confidentiality, its staff will  meet with them in person to discuss the concerns.  Witness protection can be a complex matter, and not easily summarized, however there are many strategies that can be used to help safeguard the security of witnesses.

There are protective steps that witnesses can take for themselves; strategies that WESU can recommend, protection services that the Cambodian police authorities can provide, and protective measures that the Co-Investigating Judges or The Chambers can order for witnesses during the legal proceedings, for example, they can order that a witness’s identity is hidden from the public.   As every individual is different and has special circumstances, it is usual that a witness who experiences threat or intimidation will require an individual protection plan for themselves.

Often people say the only thing they know about witness protection is what they have seen on movies, and this usually means they have seen that a threatened witness is “relocated”, that is,  moved to a new location with a change of identify. In fact, this is the rarest form of witness protection and is only used in the most extreme cases of threat in any jurisdiction, national or international. 

In relation to the protective measures that the Co-Investigation Judges or The Chambers can order for witnesses, it is important to understand that while witnesses have the right to request the Judges to order protective measures for them, they are not automatically granted on request.  Once a witness has requested protective measures, the Judges will decide whether they will grant them, and the Judges will decide what kind of measures to grant. 

The intention of the Judges is to ensure the protection of the witnesses, but before they decide on granting any witness protection measures they must consider the needs of witnesses alongside the rights of the defendants, and the need for a fair trial. The Judges will always consult with WESU before they decide on a request for protective measures for a witness.

Witness protection for the ECCC doesn’t just mean protection from physical harm due to testimony.  Many witnesses feel anxiety and fear before such a big event as testifying and they need support, reassurance and accurate information about what is happening.  WESU also concerns itself with protecting witnesses from emotional and psychological stress and that is why we have developed a range of support services for witnesses which include the provision of individual services of support to every witness from the professional staff of the Transcultural Psychosocial Organisation Cambodia (TPO Cambodia).

Ms. Wendy Lobwein is Coordinator in the ECCC's Witnesses/Experts Support Unit.

Protective measures in the ECCC proceedings are reguleted in Internal Rule 29 and Practice Direction on Protective Measures

Most read

In 2013, starting a blog is hardly something revolutionary.  So why have we then decided to do just that?

Mr. Chhaom Se, a witness who first appeared on 11 January 2013, was given a chance to complete his testimony when...

Stay connected