Between 1998 and 2005, a wave of murders targeting elderly women hit Mexico City, triggering the hunt for and capture of a most unlikely suspect.

The year 2000 marks the start of a new decade in Mexico City. A number of murders has the capital police at a stalemate: older ladies are being strangled in their own homes. The victims' profiles are causing never-before-seen social outrage and media coverage. The Attorney General's Office is employing all its resources and efforts to capture Mexico's first serial killer. Witnesses describe the suspect as tall, robust, and strong, passing off as a nurse to earn the victims' trust. In January 2006, after more than 40 murders, several failed arrests, and multiple contradictions, a woman is detained in broad daylight. Her name: Juana Barraza. Known in the world of lucha libre as "The Lady of Silence" and baptized by the media as "The Old-Lady Killer", a nickname that is to become part of Mexico's dark history as well as its incomparable pop culture.