How does the body of a missing person transform into a river in Colombia?
A few years ago, Colombian microbiologist Luz Adriana Pérez and forensic anthropologist Ana Carolina Guatame asked this question during a research project involving victims of the armed conflict in Colombian territory.
And the question arose from the testimonies they collected: dozens of them pointed to paramilitary groups as the main responsible for the violence — the lifeless bodies were thrown into the rivers to avoid being found.
In fact, a paramilitary commander, Ever Veloza, better known as HH, once said, “If they took the water from the Magdalena River, they would find the biggest cemetery in the country.”
So far, Colombian authorities have reported that more than 1,000 bodies of people considered victims of the conflict that has affected the country for more than 50 years have been rescued from Colombian rivers.
“But from the stories we’ve heard and according to official data, that number is much higher,” microbiologist Pérez, who works for the Equitas Foundation, told BBC News Mundo (the BBC’s Spanish-language news service).
So she and Guatame started asking themselves questions: How do you look for a body in a river? How can you do this quest with a lot of moving water?
“Our first effort in working on these questions is to try to give answers to those looking for information about their loved ones,” says Pérez.
“And we found that, due to the complexity of the search in rivers and lakes, there was no model similar to what had been done in the search for missing persons underground.”
And so the project was born to create the first mathematical model capable of finding the bodies of the disappeared in Colombia’s waterways.
The model
However, once the two scientists began planning the project, they realized they needed to form a multidisciplinary team, ranging from mathematicians and fluid mechanics to forensic anthropologists and even underwater archaeologists.
“It was only with our scientific specialties that we knew that we would not be able to cover everything we had as a goal. We needed more researchers from other sciences.”
One of the main challenges was measuring water: its movement in nature, but also those dynamics that affect it and are related to social and human events, such as an armed conflict.
In other words, a whole new field of research.
So, they decided to join the Instituto de Águas at Universidad Javeriana in Colombia, led by engineer and specialist in environmental hydrodynamics Jorge Escobar.
“We had never worked with this, but we were driven by the social responsibility to do something with our ability to help answer these questions,” Escobar tells BBC News Mundo.
“The first thing we had to find was a river where, in addition to having reports of bodies that were dumped there, it also had the minimum security conditions to be able to carry out our investigations”, he explains.
After several months, the river chosen was La Miel. This tributary of the Magdalena, located in the department (State) of Caldas, about 500 kilometers west of Bogotá, had the particularity of being in an area of conflict between the municipalities of Norcasia and Samaná.
“But also, being part of the tributary of a dam, it somehow allowed us to have a controlled current for several months of the year”, explains Escobar.
Both the team led by Pérez and Guatame and Escobar spent several months on the banks of the river, in its waters and even under it.
“The main thing was to make a characterization of the river”, he explains.
Rivers are generally composed of three hydraulic accidents: eddies, jets (waterfalls that can be small or large) and backwaters (where the river current is calmer).
To characterize the river, he explains, is to see where each of these accidents is located.
Then, with these well-identified points and with the help of satellite photos, they started to measure what happened to a body when it crossed the watercourse and came across these accidents.
“We used a ‘dummy’ (dummy or puppet) that we named Emilio. And we measured both the movement of the water at these points and the movement of the ‘dummy’ to be able to draw various conclusions”, emphasizes Pérez.
All these measurements and the subsequent analysis of that data lasted about two years, including the period of the Covid-19 pandemic, and left a mathematical model by which the river and its “behavior” can be recreated.
The study showed points of interest where the bodies or remains of the missing could be found. These locations were named Geomorphological Units of Forensic Interest, or UGIF.
“But, above all, this gives us certain standards that can be applied to any body of water in Colombia where this type of search is carried out”, points out Escobar.
underwater archeology
However, it was essential to consider a detail: the human body, unlike the mannequin, does not always float.
“By having the UGIF with the measurements taken in the river, we had to incorporate the underwater data into this model: what happens to the body when it sinks and, more importantly, when it decomposes,” notes Pérez.
To do this, the team members did two things: first they called in archaeologist Carlos del Cairo, an expert in underwater exploration, and then they placed the body of a pig at various points in the river to see the effect of water on the process of decomposing organic tissues. .
For Del Cairo, who had worked on the discovery of several colonial shipwrecks off the Colombian Caribbean coast, working on the river brought several different demands.
“You go from working on a research surface of hundreds of square meters with good visibility to a river with minimal visibility in some parts,” explains Del Cairo.
However, what posed a greater challenge was finding patterns to trace elements such as bones or clothing scraps such as belts or straps, pieces of pants or shirts.
“We had to adapt our measuring equipment to underwater surfaces to find objects that are a little more unusual. It’s not the same as looking for jars or boat remains,” he explains.
All the data obtained —between the exploration carried out by Del Cairo and the results of the decomposition of the animal— were able to complete the initial phase of the project, which had already advanced with the characterization of the river.
“These data first allowed us to be more certain about possible sites of interest for our research, but also helped to consolidate patterns to have a predictive model for the search for human remains in the water,” Puerta said.
So the team selected several points on the bed of the La Miel River.
“With these points, we hope to carry out a real search for the bodies of the missing in La Miel in the coming months, to complete the design of the mathematical model”, explains Pérez.
This research, the scientists point out, highlights the importance of water in the country.
“About half of Colombia’s territorial area is water: sea, rivers, lakes. Therefore, if we are going to make an effort to seek the truth about what happened in the country, it is essential that we support these scientific processes to provide answers that are possibly in the course of rivers in Colombia”, explains Escobar.
“Colombia was built around its rivers”, concludes Del Cairo. “That’s why we can’t escape the responsibility of looking for ways to help rebuild what happened in the country.”
