Filter paper as a blood sample collection device is most commonly associated with the biomedical sciences: the infant’s toe pricked for a drop of blood during neonatal screening. These pieces of filter paper were submerged in the thoracic cavity of bodies during necropsy as soon as they were opened. This technique is a quick, fail-proof method of obtaining blood samples (and later, DNA) from well-conserved unidentified human remains. None of these samples belongs to a San Fernando victim or to similarly deposed or decomposed bodies. Since 2006, close to 2000 clandestine mass graves have been found in Mexico. This sampling method is useless for the bodies recovered from these sites.
This photo was taken on 7-14-17 during my ethnographic fieldwork.