It has been over seven years since 43 students from the Ayotzinapa Rural Teachers’ College in Guerrero, Mexico, were taken by armed men in the middle of the night. They were never seen again. Their disappearance sparked mass protests, as the 43 became symbols of Mexico’s unchecked human rights abuses. In recent decades, tens of thousands of people have gone missing in Mexico, and almost no one has been held accountable. The culture of impunity is so ingrained that families often don’t go to police for help, believing they’re either corrupt or too afraid to investigate.

In the first part of a three-part investigation of the Ayotzinapa case, Reveal’s Anayansi Diaz-Cortes and Kate Doyle from the National Security Archive take us inside the investigation into the attack on the students.

For parts two and three, go to the Reveal podcast feed.