Juana Barraza AKA ”The Old Lady Killer”

Our first female serial killer, Juana Barraza, aka The Little Old Lady Killer!  Her whole story is packed into just one episode (since we don't read/speak Spanish, and she didn't talk much)!

Sources:

The Little Old Lady Killer: The Sensationalized Crimes of Mexico's First Female Serial Killer.  By Susana Vargas Cervantes

Murderpedia.com

Juana Barraza criminal minds wiki