Serial Killers Sisters: Las Poquianchis Between 1945 and 1964, four sisters from Jalisco-María Delfina, María del Carmen (possibly), María Luisa, and María de Jesús González Valenzuela-operated a criminal enterprise across three Mexican states that resulted in 212 confirmed murders. Journalist Martín Delgado followed the case from its 1964 discovery through the trial, sentencing, and the sisters' deaths in prison. His investigation revealed not supernatural evil, as sensationalist media claimed, but systematic exploitation enabled by poverty, corruption, and societal indifference. The sisters recruited desperate women through false advertisements, trapped them through debt bondage and drug addiction, and murdered them when they became unprofitable. The operation required extensive complicity: corrupt officials, willing suppliers, paid accomplices, and communities that looked away. Even basic facts remained contested-birth dates, number of victims, circumstances of the sisters' deaths-as mythology consumed reality. Delfina died in prison in 1968 (circumstances unclear), María de Jesús by suicide in 1969, and María Luisa reportedly in 1984, though records conflict. Their story became legend, but the systemic conditions that created them-poverty, corruption, exploitation of vulnerable women-persisted unchanged. The case revealed uncomfortable truths: that ordinary people enable extraordinary evil, that monsters are made not born, and that society prefers mythologizing criminals to examining its own complicity.