On Location Video: The ghosts of El Diamante Ranch

VERACRUZ, Mexico — At an abandoned ranch in Tres Valles called "El Diamante," the marines made a grim find: a grave containing the remains of at least 31 people. Only eight have been identified so far. Five of them belonged to the family of Berta Diaz Torres.

"[They were] my daughter and my four grandchildren," she says, seated quietly in front of her small home. "Imagine my surprise when I saw that [my daughter] died from being stabbed and having her throat cut. I can't sleep at night thinking about it."

The origin of the crime is still under investigation. But it's not a new phenomenon, in a country that's suffered a string of massacres and mysterious mass graves since 2010.

"I don't know what my daughter got up to," Torres says. "But if she owed something then I think she's paid it."

More from GlobalPost: The worst massacres and mass graves in Mexico’s drug war