Q&A: Identifying mass graves

The discovery of the remains of at least 3,000 people in al-Mahawil, south of the Iraqi capital, Baghdad, has raised the question of how investigators will identify the victims. UN experts from the war crimes tribunal at The Hague explain what happens what next.

What is the first thing investigators will do?

The first thing that investigators would do is to try and determine the basis and extent of the crime or crimes committed - who, what, when, where, how and why?

From this it might be possible to determine who the victims are and from what group the suspects come from.

In some cases it might be possible to determine who the suspects are.

What are the main difficulties in identifying victims?

The methods used to kill people can complicate identification.

For example, if people have been killed in a blast or explosion it is likely those mortal remains will be mixed and dispersed.

On the other hand if people were killed by a single gunshot those bodies are far more likely to be intact.

It also should be noted that if an individual is buried in a single grave it is far easier to identify him or her than it is to identify groups of people from a mass grave.

What techniques will be used?

All techniques used for the recovery of mortal remains derive from archaeological methods, though there's no specific method that covers all exhumations.

Each site needs to be individually evaluated but in as far as it is possible, mortal remains are recovered in reverse order to the method by which they were buried.

Initially the material used to cover the mortal remains would be removed first, eventually the actual mortal remains being recovered.

If bodies have already been unearthed, how much more difficult is the job?

Any unskilled involvement in retrieving the bodies may damage them.

This is particularly the case where bodies are intertwined, as they will be in a mass grave site.

In these cases they'll need to be separated by forensically qualified staff.

These skilled professionals would be experts in the identification of the various body parts and would readily identify bones in particular.

It's far more likely that bodies will become mixed up or have parts left behind by non-professionals in this area of work.

This would or could add to the difficulties in determining the cause of death.

How easy is it to tell if they have been murdered?

As long as the injuries that caused the loss of life have affected the skeleton and not the soft tissue, there is a strong probability that the cause of death can be determined.

If injuries have only affected the soft tissues and the soft tissue no longer exists then the job becomes much more difficult, and it might not be possible to find out how a person died.

What evidence might there be to lead to those who carried out the killings?

There are two kinds of evidence that might assist in this area, material evidence and inferred evidence.

These would include possibly some of the following:

Shell/munitions casings, handcuffs or ligatures used to tie hands or feet etc.

Anything that might have been dropped by the perpetrators such as ID cards or other material that might identify them.

Markings left by heavy plant equipment that might have been used in disposing of the mortal remains.

The victims - who would want to kill them and background investigations.