India, July 29 -- Scientists in Mexico are dressing dead pigs in clothes before disposing of their bodies. The bodies are wrapped in packing tape, while others are chopped and stuffed into plastic bags or wrapped in blankets. The bodies are then covered in lime or burned. Some of them are buried alone and others in groups.

The scientists then watch. The pigs are proxies for humans to help find the large number of people who have gone missing in Mexico after decades of drug cartel violence.

Government scientists are using satellites, geophysical and biological mapping techniques and the pigs to help discover some of the 130,000 missing bodies. Families, not authorities, often lead searches, guided by witness tips and crude tools to find ...