Editor's note: This story includes graphic descriptions of the search for human remains.
Manky Lugo has developed a gruesome expertise. Like a human bloodhound, she sniffs out traces of death.
Her gray hair wrapped in a bright-green bandanna, the 64-year-old applies her skill during an annual search for remains of fellow citizens who have vanished without a trace — victims of Mexico's drug wars and armed groups. A loved one of her own is among the missing.