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On 7 July, the ICTY investigators began a first series of exhumations. Until mid-September, they will visit about ten sites.
So far, nearly 150 bodies have been unearthed.
This document presents the process of mass-grave exhumations, which is a milestone in the rendering of international justice.

Forensic investigation of mass grave sites marks a departure for the international legal community. Prior to the 1980s, human rights abuses were documented almost entirely through witness and victim testimony. In 1984-5, forensic scientists from the United States, working under the auspices of the American Association for the Advancement of Science, exhumed skeletal remains of disappeared persons in Argentina. They provided physical evidence for the trial of members of the deposed military junta and trained an Argentine forensic anthropology team. It became apparent that medical and forensic verification of torture and extra-judicial executions could provide irrefutable evidence that such activities had taken place.

In recent years the Boston-based association Physicians for Human Rights (PHR), which has been at the forefront of this type of work, has conducted missions to 30 countries.

Definition

There is no legal definition of mass graves. Mr. Bacre Waly Ndiaye, the UN Special Rapporteur on extra-judicial, summary or arbitrary executions, has defined "mass graves" as locations where three or more victims of extra-judicial, summary or arbitrary executions were buried, not having died in combat or armed confrontations.

Why exhumations?

The purpose of the Tribunal's exhumations is threefold:

(1) To corroborate witness testimony.

(2) To recover evidence related to events reported in Tribunal indictments.

(3) To document injuries and identify the cause and date of death.

How important is forensic evidence in establishing criminality?

Of themselves, mass graves do not provide proof of criminality, as there are a number of possible explanations for their creation. However, in support of witness testimony, they can provide powerful evidence that crimes such as summary executions were committed.

As John Gerns, forensic expert of the ICTY, says, "Regardless of the reliability of the witness, testimonial evidence without corroborating physical evidence can be the most contentious and weak form of evidence in an investigation or during the subsequent trial."

Has forensic evidence from mass graves been introduced in previous international criminal prosecutions?

The admission of forensic evidence from mass graves during prosecutions before the International Criminal Tribunal for the Former Yugoslavia (and before the Rwanda Tribunal) will be an historical first. Such evidence was not produced during the Nuremberg or Tokyo Trials - the only previous "international" trials (though such trials cannot be considered truly international; see the article in Bulletin No. 5/6, 24 April 1996, comparing the ICTY with the Nuremberg IMT). This failure is explained by the relative modernity of the techniques used in exhuming mass graves. Forensic anthropology is a recent science.

Is permission required before a mass grave can be exhumed by Tribunal investigators?

Under the Dayton Agreement, the Tribunal has to be granted free access to mass grave sites. However, a chain of custody procedures must be followed.

Co-operation of local governments

Local governments, particularly those of Croatia, Bosnia and Herzegovina and Republika Srpska, are expected to co-operate with the work of mass grave investigators by alerting them to the location of possible sites and by guarding those sites. In addition, they are expected to defer to the Tribunal when it wishes to exhume a particular site.

The Office of the Prosecutor (OTP) has requested the local authorities to refrain from carrying out their own exhumations without first co-ordinating with the OTP, and to secure sites under their control to prevent tampering.

Relation to the recent conflicts

Not all of the mass graves in the former Yugoslavia may be related to recent conflicts. Some could contain remains dating back to conflict in the same territories during World War II.

Additionally, not all of the mass graves believed to exist were necessarily created in violation of the Geneva Conventions and its Additional Protocols. It is conceivable that some could contain the bodies of combatants, buried collectively for sanitary or other legitimate reasons. Similarly, some could contain the bodies of civilians who were buried collectively for legitimate reasons.

In the final report of the Commission of Experts Established Pursuant to SC Resolution 780 (1992), the Commission noted that the existence of mass graves does not necessarily mean that persons were unlawfully killed. However, several provisions of the Geneva Conventions cover the treatment and burial of those killed during wartime. In some instances, these provisions may have been violated by those burying the dead in collective graves without proper identification. Thus, beyond a mass grave's importance as a repository of evidence of mass killing, the method by which the grave is created may itself be a war crime. It is believed that all of the mass graves so far identified in the former Yugoslavia contain civilians caught up in the recent war. Significantly, all of the sites identified so far by the Tribunal have been unmarked.

How do investigators discover mass graves?

Photographing the remains

In connection with a particular investigation, the Tribunal asks governments to inform it of mass grave locations. It also relies on witness and other testimony in locating grave-sites.

In certain cases, the Tribunal has used satellite photographs, made available by Western intelligence agencies, to help locate areas of disturbed earth and vegetation. Such photographs, says John Gerns, can narrow the potential area of search "from a country to a football field".

How are recent sites distinguished from older ones?

The fact that exhumations are only conducted pursuant to an investigation means that investigators have been tipped off about relevant areas to search. Additionally, forensic experts have techniques for establishing the time and cause of death, even with very old remains. Coupled with non-forensic investigations and inquiries, these tests enable investigators to avoid confusing pre-existing and recent mass graves.

How many mass graves will be exhumed by the Tribunal?

It is impossible to put an exact figure on the number of mass graves in the former Yugoslavia. In any event, the Tribunal will conduct exhumations only in connection with an OTP investigation. "We are only interested in grave sites relevant to our indictments or indictments we may issue in future," said Chief Prosecutor Richard Goldstone. "It's not our business to exhume mass graves other than for forensic reasons relating to prosecution charges."

In total, the Tribunal's investigators intend to exhume approximately 20 sites, located in Croatia and Bosnia and Herzegovina. The exact location of these sites is classified, and will be progressively disclosed. The first grave exhumed in July was at Cerska, not far from Srebrenica. Prior to July, the Tribunal conducted two exhumations: one in Croatia and one in Bosnia and Herzegovina. Fifteen bodies were exhumed from the Bosnian site, located in Ramici. The mass grave site in Packracka Poljana, Croatia, contained 19 bodies.

In addition, more exhumations have been carried out by the governments of Croatia, Serbia and Bosnia and Herzegovina. These are primarily for the purposes of identification of missing and disappeared persons, but also to support prosecutors in their national courts. While not conducting such exhumations themselves, Tribunal staff at times observe the activities. In the past few months, Tribunal staff have observed two exhumations by the Croatian government, and another in which the Serbian government exhumed 181 bodies near Mrkonjic Grad. Investigators also worked with the Bosnian government on a site at which two graves and 25 bodies were uncovered near a bridge by Sanski Most.

Preparatory work

Prior to starting an exhumation, forensic experts identify sites by making preliminary trips to suspected areas. They use high-tech equipment, such as electronic mapping procedures, to measure and map precisely the entire grave area, artefacts, human remains and other objects. The team searches for bodies by using a two-metre, T-bar-shaped steel probe, which is plunged into the ground and smelled for the odour of decayed remains. Investigators establish the grave's approximate perimeter by gauging soil density and hardness.

A test trench may also be dug to the depth of the bodies in order to locate their positions. The position of the bodies can be a key to establishing how the victims were killed and their remains disposed of. For example, in a trench dug in late May in Nova Kasaba, near Srebrenica, two bodies were found with hands tied behind their backs, one with wire and another with shoelaces. The positions can also reveal whether victims were lined up and shot, and from what angle, and whether they were bulldozed into the site after being executed.

The exhumations

The size of the investigating team depends on the size of the site to be exhumed. On an average site (say, 100 bodies) the investigating team might include two forensic pathologists, who recognise and interpret diseases and injuries in the human body, two forensic anthropologists, who specialise in knowledge of the skeletal system, and two forensic archaeologists, who apply archeological recovery techniques to death scene exhumations. In addition, approximately three OTP staff members and a legal advisor are present, the latter to observe and record the proceedings. The number of workmen at the dig depends on several factors, including the size, distribution and complexity of the site. The host government normally has an investigating judge on site, who remains there from the moment ground is broken until bodies are removed.

Security for the whole operation is provided by the Implementation Force (IFOR). The troops' mission is limited to providing personal security for the investigating teams.

Techniques

Evidence of a sharp force injury (ex. Machete blow) to a finger bone.

Once the preparatory work has been completed, the area is excavated, using a backhoe if the site is accessible to heavy equipment. This is used to remove shallow layers of soil until the bodies or their clothes are revealed. If the site is inaccessible, the soil is removed using manual diggers with shovels, under the supervision of the forensic team. Once the diggers near the level where the bodies are buried, the forensic team steps in. Investigators unearth the remains using small digging instruments to ensure that no evidence is damaged or disturbed. They also search for and remove items such as teeth - which can be essential in identifying persons - and personal effects.

In addition, the investigators recover any other relevant evidence, such as shell casings and bullets. They also study the site around the grave to determine whether there is evidence of an on-site mass execution. This might be indicated, for example, by the presence of a pattern of bullet holes on nearby trees.

Finally, the team carefully removes samples of plant and insect remains, which are later studied to help identify the time of death. The entire exhumation process is recorded using still photography and video.

Duration

Exhumation in progress with large waterdrainage tent overhead.

The process of exhuming a mass grave containing approximately 100 people takes about one month. This only includes the physical exhumation and not the forensic and pathological examinations.

After the exhumation

After the remains and other evidence have been exhumed, they are sent to a forensic laboratory for examination. At the lab, the remains are first x-rayed, after which a forensic autopsy is performed, with the goal of identifying the victim, documenting injuries, and determining the time and cause of death.

To identify a victim, pathologists attempt to determine the stature of the deceased, his or her sex, age, and whether he or she was right or left-hand dominant, etc. The latter is adjudged by studying the bones of the forearm. In a right-handed person, the right forearm is longer than the left, and vice-versa.

Central to the identification process is the forensic examination of bones. The size and shape of bones recovered from mass graves indicate the sex and age of victims. For example, men's pelvic bones are larger than women's, as are their brow ridges, jaw bones and bones behind the ears. A victim's age can be gauged by studying the calcification of bones and sutures in the skull.

Bones can also reveal the cause of death. Entry and exit wounds can show the manner in which a victim is killed. A pattern of bullet holes in a particular place, for example, the base of the skull, may indicate a mass execution, rather than death in combat.

During the autopsy, sections of femur may be collected to enable DNA analysis to be conducted at a later date for a definitive identification. Identification is facilitated if the deceased's dental records can be traced. If possible, the pathologists take fingerprints. Forensic investigators also take sections of clothing which may assist in the identification process. Once this thorough scientific procedure has been concluded, an autopsy report is issued.

It is important to note that autopsies are not conducted on all the remains in any particular mass grave. The percentage given post-mortems is determined by the grave's size. The goal is to try to establish patterns of death/behaviour and any inconsistencies.

Examination of other evidence unearthed from the grave-site, such as bullets, bullet fragments or shell casings, is also undertaken by a laboratory set up to undertake firearms and toolmark analysis.

Following a post-mortem or handling by the Tribunal's forensic team, the remains are returned to the national governments. If identified, they are returned to their next-of-kin. It is unclear what the governments of Bosnia and Herzegovina and Croatia do with remains that are unidentified, and particularly, if they are buried singly or collectively, and where.

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