State prosecutor Jorge Winckler said the clandestine burial pits appear to contain the victims of drug cartels killed years ago. When they find what they believe are burial pits, they alert authorities, who carry out the final excavations. Drug cartels in other parts of Mexico have deposited victims’ bodies in mass graves before. Those burial pits were excavated in part with the use of backhoes. Drug gangs in some places in Mexico have taken to burning or dissolving their victims’ bodies in corrosive substances in order to avoid discovery.

Source: The Guardian March 14, 2017 17:10 UTC