In part due to an encephalitis infection, he showed abnormal behavior as a child, including cruelty to animals.

Cárdenas received a scholarship from Pemex to study chemistry at the Universidad Nacional Autónoma de México (UNAM).

On 15 August 1942 he was visited in his house in the Tacuba neighborhood of Mexico City by 16-year-old prostitute María de los Ángeles González.

In the following weeks he also murdered prostitutes Rosa Reyes and Raquel Martínez de León, both aged 16, and finally 19-year-old fellow chemistry student Graciela Arias Ávalos.

He was invited by interior secretary Mario Moya Palencia to give a speech in the Congress of the Union, where he was celebrated as a hero.

A chance meeting with Alejandro Jodorowsky in a backstreet bar in Mexico City inspired the psycho-magician to create the 1989 film Santa Sangre, based loosely on Cárdenas's life.