Juana Barraza Samperio was born in Hidalgo state on December 27, 1957, to an alcoholic mother who, she said, gave her to a man in exchange for three beers when she was twelve. She had four children, worked as a professional wrestler under the name La Dama del Silencio, the Lady of Silence, and was known on the lucha libre circuit.
Between 1998 and 2006 at least sixteen elderly women, and by some counts up to forty, were strangled in their own homes in Mexico City, usually with a stocking or a stethoscope, after the killer had talked their way in by offering help with shopping or claiming to be from a government social programme. Small items were taken. The Mexican press called her La Mataviejitas, the Old Lady Killer.
The investigation was a study in assumption. Witness descriptions were of a large, heavily built person, and investigators concluded the killer must be a man, then that he must be a man dressed as a woman, and rounded up transvestite sex workers across the city. A criminal profile was published describing a male suspect. The press called the case El Mataviejitas, the little-old-lady killer.
She was caught on January 25, 2006, running from the house of an eighty-two-year-old woman she had just killed, by a lodger who saw her leave. Fingerprints matched those from a dozen scenes. She was convicted in 2008 of sixteen murders and given 759 years, a sum of consecutive terms rather than a sentence anyone could serve, reduced on appeal to a term that keeps her in until 2058. She has admitted four.