On August 29, a little after midday, Maura Cordero, the owner of an arts and crafts shop in the small town of Acatlán in the central Mexican state of Puebla, noticed an unusual number of people gathering outside the municipal police station next to her shop.
Cordero, 75, moved closer to the door and peered out. Dozens of people were outside the police station on Reforma Street, the town's main thoroughfare, and the crowd was swelling.
Soon there would be more than a hundred people. Cordero could not remember seeing such a crowd in Acatlán except at a holiday celebration. As she watched a police car passed her shop bearing two men int