What are the main tasks of the forensic pathologist in mass disasters?

In the regions around Kiev, such as Boutcha and Marioupol, the recent discovery of mass graves has provoked horror. The Ukrainian authorities have announced the massacre of hundreds of civilians by the Russian army, which the Kremlin denies.

Laurent Martrille, University of Montpellier

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Over 7,000 investigations have been launched in the last two months by Ukrainian Prosecutor General Iryna Venediktova, and many countries (including France) have sent teams of experts to help.

Generally speaking, what are the roles of forensic scientists in mass death situations? And how do international collaborations work? Laurent Martrille, forensic pathologist and senior lecturer at the University of Montpellier, is a member of the Société française de médecine légale et expertise médicale (SFMLEM) and the Équipe de droit pénal et sciences forensiques de Montpellier (EDPFM). He is also a reservist doctor at the Institut de recherche criminelle de la gendarmerie nationale (IRCGN), and has already been commissioned by the International Criminal Court.

The Conversation-France: What are the main roles of a coroner in a mass death zone?

Laurent Martrille: The forensic pathologist has two functions: to identify victims and to investigate the causes and circumstances of death.

However, in this context, victim identification is the main task in which the forensic pathologist is involved. Each country has specialized teams for this purpose.

In France, the UNIVC (Unité nationale d'identification des victimes de catastrophes) is in charge; it itself comprises two sub-units, theUGIVC (gendarmerie) and the UPIVC (police). Each unit is made up of police officers or gendarmes (including specialists in DNA, fingerprinting, etc.), forensic doctors and forensic dentists.

UGIVC is part of the Institut de recherche criminelle de la gendarmerie nationale (IRCGN) and can operate anywhere in France, as well as being deployed internationally (a team has been dispatched to the Lviv region, editor's note]). It is equipped to intervene remotely - radio, DNA analysis, autopsy, etc.

The second role, investigating the causes and circumstances of death, is not systematic: the authorities concerned may or may not give this mission. After the tsunami in Thailand on December 26, 2004, for example, the mission was solely one of identification. Things can be different when a third party may be involved, whether in an accident, an attack or a war.

TCF: When there are so many deceased to identify and the specialist teams on site come from different countries, how do they work together?

L.M.: There's no room for improvisation (even if every disaster is different and requires adaptation). All procedures were tightened up after the 2004 tsunami, when over 5,000 bodies had to be identified. This gigantic modern disaster enabled us to set international standards.

The work is now carried out according to standardized procedures laid down by Interpol and accessible to all: the so-called "Disasterar Victim Identification" (DVI) procedures. This enables teams responding to large-scale disasters to share protocols and results.

With regard to identification, these international standards are based on three so-called primary identifiers, which must be absolutely respected. A body can only be identified if one of them has been used: fingerprints, DNA or odontology.

To enable identification, two types of data must be collected and compared:

  • Post-mortem data, collected in the field and on the body by forensic pathologists, dentists, sometimes anthropologists, and fingerprint specialists.
  • Ante-mortem data, collected from families or, where appropriate, from authorities in other countries.

Interpol offers extremely precise post and ante mortem forms to fill in, with rigorous coding to facilitate data comparison. Cross-checks are made using software, but in the end it's an identification commission made up of judicial and local authorities from the countries concerned, forensic experts, dentists, investigators... who check everything before making a final decision.

In such circumstances, there are two main principles to respect: protocol and nothing but protocol... and adapting to the case in hand, as each mission has its own particularities, often very different from one situation to another. When you're called out after a tsunami or an aircraft crash, the circumstances are very different.

TCF: At what point does the medical examiner become involved?

L.M.: In theory, the forensic pathologist can intervene at any stage of the process. However, except in special cases, he or she does not usually take part in what we call body collection or, depending on the situation, exhumation - there are specialized teams for this, although a forensic pathologist may accompany them. There may be an advantage to our presence on site when there are very few bodies.

When there are a large number of deaths, the added value of our on-site intervention is limited. Moreover, even if the identification teams can be mobilized quickly, out of respect for the deceased, it is not possible to leave bodies on site, in the streets for example, before the arrival of the forensic experts. There is then an initial "collection", which is carried out by the local authorities, without Interpol coding.

This was the case for the tsunami: the bodies were initially numbered according to Thai standards, then renumbered to enable international collaboration.

The specialized teams in charge of this stage follow Interpol procedures, with very precise numbering and coding. Each body or body part is placed in a separate bag, identified... Everything is planned and organized, and then the bodies are transferred to the morgues where we operate.

Another point: in some cases, the area may need to be secured by deminers or specialists trained in NRBC (nuclear, radiological, biological, chemical) risks. They ensure that there is no or no longer any risk, or decontaminate the scene if necessary. The bodies themselves may have been contaminated (chemically, biologically) or even trapped.

So there's a lot of checking to be done upstream, to prevent doctors and investigators from being exposed to additional threats. It's quite rare, but it's a very onerous requirement.

TCF: All these upstream interventions will delay the moment when forensic teams can intervene. Is there a risk of losing information?

L.M. : Obviously, it's not possible to leave bodies exposed to the open air for long periods. This is why, depending on the case, initial exhumations are carried out to ensure (very) relative preservation. Ideally, bodies should be placed in refrigerated cases.

If the remains are scattered over a fairly large area, they can't be left for days on end, while things get organized and a forensic pathologist carries out in situ body recovery... it's common sense and a minimum of respect for the deceased.

The collection of the bodies, even if carried out with the utmost precision, will inevitably interfere with the subsequent investigation. But by following international protocols, we can start working with the elements collected on site.

The most important thing is to implement solutions for storing bodies at low temperatures. The usual storage temperature is 4°C. In Thailand, there were dozens and dozens of refrigerated containers.

TCF: How do you go about identifying the bodies that arrive at the morgue?

L.M. : Depending on the circumstances (number of bodies, state of preservation, etc.) and the human resources available, when a body arrives, we usually take X-rays, and now scans (when possible). This enables us to keep accurate digitized data once the body has been returned to the family.

The investigators then set up two identification chains:

  • The "X supposed to be so-and-so" approach: when a body, for example, is carrying papers. This allows us to move a little more quickly, as there are clues to guide the search. But there's no certainty: you could be carrying someone else's papers...
  • The "X" system: when there is nothing to suggest identity.

The first station in these chains is usually fingerprinting. Next, we begin by examining and describing the clothing before undressing the body; if necessary, samples can be taken at this stage (of hydrocarbons, etc.), at our suggestion, by specialized technicians.

Anything recovered from a body, such as that collected on site, is sealed under conditions that will enable it to be analyzed at a later date. Each sample is individually sealed and packaged.

Once undressed, the body undergoes an external examination to note anything that might help identify it or make comparisons: measurements, tattoos, clothing, wounds and scars, etc.

In such cases, forensic anthropologists are called in. Obviously, much data is lost, such as fingerprints, but the bones retain information on age, sex, height, biogeographical origins and, where applicable, traces of trauma.

At the end of this stage, a DNA sample is taken. This may be at a wound if the body is fragmented, or through an incision in a muscle. Dentists come in last.

But if the bodies have been piled up in mass graves, for example, or handled carelessly during removal, the risk of contamination by another body is very high: the value of contact DNA, which would make it possible to identify people who touched or harmed the victim during his or her lifetime, is then compromised. As a result, the relevance of such surface samples is limited.

At the end of this chain, a quality control check is carried out to ensure that nothing has been overlooked. In France, the 86 victims of the Nice attack on July 14, 2016 were identified in 4 and a half days.

Identification elements are therefore provided jointly by the dentist, the forensic pathologist and even the anthropologist. Note that the forensic pathologist does not identify the body: he or she, like the anthropologist, provides identification clues, but takes DNA samples for later analysis. The dentist, on the other hand, will provide the elements directly required for identification by the identification commission. On the other hand, the only person who can give an opinion, if requested, on the cause of death is the forensic pathologist.

TCF: What happens if the forensic pathologist is asked to investigate the cause of death?

L.M.: Autopsies to investigate the cause of death are only carried out at the request of the authorities, as this is not UNIVC's usual remit.

As mentioned above, any external items taken from the body are handed over to the investigators: clothing, but also possible ties and personal effects, etc. These items may be sampled for later analysis. Samples may be taken from these items for subsequent analysis.

In addition, we look for any traces of injury or violence on the integuments, but also by autopsying the body. If the body has been subjected to torture or violence, the description of any injuries will be crucial to understanding the circumstances leading up to or during death.

When the death is recent and the body has been preserved in optimal conditions, the marks are still perfectly studyable and we can give fairly precise information.

The more time passes, the more complicated it becomes. Putrefaction will interfere with external examinations, yet skin analysis is essential as it provides vital information on the type of injury (ballistic, blunt impact, ligature marks, etc.).

However, even when bodies are so degraded that only bones remain, elements can still be found. Traces on the bone, if they exist, are "frozen" in time: the bone retains the memory of traumas and their mechanisms. However, determining the cause of death becomes much more complicated, and often impossible... For example, we may find a significant cranial trauma, fatal in itself, but if the cause of death is secondary to the passage of a bullet through the body without marking the bones, we will see nothing (the cranial trauma observed may have been perpetrated after death).

It's also important to remember that we don't work alone: all forensic laboratory experts (in ballistics, toxicology, DNA, entomology - dating the moment of death from necrophagous insects -, fire trace analysis, soil analysis, etc.) can be called in.

All stages of the procedure are documented by photos, and sometimes filmed. This extreme rigor is essential to enable discussions between experts and limit any possibility of later dispute.

Once the identification and/or autopsy operations have been completed, the bodies are prepared (as far as possible) for presentation to the families, who have the right, under all circumstances, to see them before burial. Families are supported during this very difficult time. The aim is to return the deceased to their loved ones as quickly as possible, as soon as identification is certain.The Conversation

Laurent Martrille, Senior Lecturer at the University of Montpellier, hospital practitioner at Montpellier University Hospital, EDPFM, University of Montpellier

This article is republished from The Conversation under a Creative Commons license. Read theoriginal article.