Unearthing Grave Offenses

Historical Archaeology, Vol. 35, No. 1, Spring 2001, Tucson

Two years ago, forensic archaeologists from a dozen countries excavated mass graves in Kosovo where massacres reportedly took thousands of civilian lives. Ousted Serb despot Slobodan Milosevic will face the evidence those investigators collected when he stands trial for war crimes next year. Indeed, dozens of governments and international organizations have taken to the courts to deal out penance for past war crimes and abuses of power. At least 21 new democracies have launched truth commissions in the last 15 years, and international criminal tribunals, such as the one Milosevic must face, have prosecuted atrocities committed in the Balkans and Rwanda.

Much of the evidence needed to try such crimes lies in mass graves. Investigators in Guatemala, for instance, used clothing, sex, or the angles of bullet and machete wounds to determine whether unmarked graves contained guerrilla soldiers or summarily executed civilians. Demand for that kind of archaeological expertise has boomed. Forensic pros from Argentina, for example, have taken the sophisticated excavation techniques they used to uncover their country’s past and applied them in Haiti, the Balkans, Brazil, El Salvador, Colombia, Peru, Rwanda, Ethiopia, and Kurdish Iraq.

Because the field is so new, however, forensic archaeologists have few precedents to follow, particularly when it comes to recording evidence for trial. Writing in the quarterly journal Historical Archaeology, Physicians for Human Rights (PHR) investigator William Haglund and colleagues Melissa Connor and Douglas Scott draw on their experiences in Bosnia and Rwanda to offer a kind of instruction manual for exhuming a mass grave properly.

"The most successful method of locating graves is through witness testimony," Haglund explains — a luxury for archaeologists, whose witnesses are usually hundreds or thousands of years since deceased. "Given a general location for a grave site, a trained archaeological eye can determine differences in vegetation, soil, and microtopography that indicate a ground disturbance." Sometimes they use a simple ice pick or screwdriver to test how compacted the soil is; other times they may use an odor-detecting probe, sonar, or radar. Once investigators have marked a likely grave site, backhoes move in, digging a cross-shaped trench to determine the size of the grave and the depth of the remains. Backhoe operators can remove soil in layers just 5 centimeters deep, and monitors watch for signs of bones or clothing. Once they strike human remains, workers mark the outline of the grave site, cover the bodies in protective plastic, and fill the trenches back in to keep the evidence from decomposing.

Next, backhoe operators dig a deep trench around the perimeter of the grave. In contrast to old school digs, forensic archaeologists work from the outside of a site to the center, rather than from the surface down. That way, it is easier to extricate the fragile bodies without damaging them. Bamboo tools and brushes help, Haglund says, but when bodies are packed together, excavators must work primarily with their hands. Once extricated, corpses are counted by cranium, photographed, numbered, and transported in bags to an on-site morgue. All evidence is similarly bagged, labeled, and logged according to U.S. rules of evidence and U.N. guidelines. "The value of the procedures outlined here," Haglund explains, "lies in that they are a standard accepted by two international courts."

Not all forensic teams choose to include professional archaeologists, Haglund notes. But Connor and Scott, in a separate article, argue that full-time forensic archaeologists have excavation skills that forensic anthropologists — trained first to interpret evidence — may not. The authors recall their work at a site about two hours south of Zagreb, Croatia, at a mass grave they exhumed as part of a PHR forensic team. They decided to map the site electronically, rather than laying down a traditional string grid. That caused a minor furor among the anthropologists on-site, for whom "professional archaeology was equated with string grids and square holes." Eventually, they chose an arbitrary string grid to end the argument, although they never used it.

"Working in the forensic-science field as an archaeologist is working between two fields," the authors admit. Yet, "the continuing excavation of mass graves and individual graves seems a virtual certainty." That means a greater need than ever for experts who can dig up the past.