Since 2014 When 43 Ayotzinapa Normalistas went missing in Mexico, Silván and other CentroGeo experts joined the scientific advisory committee on the case. While searching for the students, various civilian groups and government brigades discovered dozens of illegal graves. In less than 10 months, Mexico’s Attorney General’s Office investigated 60 sites and 129 bodies in the state of Guerrero. As a result of the crackdown, about 300 illegal graves were discovered. Since then, the number of secret tombs has increased.
No one could have predicted the scale of this horror. report“Navigating Between Pain and Hope: Discovering Secret Graves in Mexico 2020-2022” uses hemerographic data to reveal that during those two years, 1,134 secret graves were registered, containing 2,314 bodies and 2,242 human remains. Proportionally, Colima reported the highest rate of illegal graves, at 10 per 100,000 residents. It was followed by Sonora, Guanajuato, Guerrero, Sinaloa, and Zacatecas.
Guanajuato, Sonora and Guerrero stand out in terms of number of cases. These three objects make up 42% of the records. By April 2023, a media investigation by Quinto Elemento Lab showed that the number of illegal burials had reached 5,696, more than half of which were detected by the current federal administration.
Using your field of expertise, remote sensingJosé Luis Silván uses images captured by satellites, drones or airplanes, and extracts geospatial information from them using knowledge of the physics of light, mathematics and programming. Multispectral and hyperspectral images are useful in searches because they capture subsurface information using sensors that record wavelengths of light that cannot be detected by the human eye.
In the first study by CentroGeo researchers in 2016, they evaluated the feasibility of using hyperspectral cameras for searches and simulated burials with pig carcasses to see what information from the sensors would be useful. Mexican researchers knew from work in other countries that successful detection using these techniques depends in part on the ability to recognize how carcasses (and their spectral images) change in different soils and climates.
The experiment was conducted on leased land in the state of Morelos. There, they buried seven animals and evaluated the light reflecting off the soil at various wavelengths over a six-month period. They concluded that hyperspectral cameras providing more than 100 layers of data have the potential to detect secret burials. However, this technology is only effective for three months after burial. They tried to arrange the purchase of cameras and drones (worth 5 million pesos) through the National Search Committee, but failed.
