In 1529, in the course of the trial conducted against Pedro de Alvarado by the Court of Appeals (Audiencia) of Mexico, many details of his misdeeds during the conquests of Mexico and Guatemala came to light. This thesis applies the principles of modern abnormal psychology to make a detailed examination of several of the charges brought against Alvarado, such as his unauthorized use of the habit of Santiago, his behavior during the massacre at Tlatelolco and the flight from Mexico as well as in the course of the conquests of Tututepec and Utatlan. The text of the 1529 Inquiry is compared with the contemporary accounts of Bernal Diaz del Castillo, Hernan Cortes, Francisco Lopez de Gomara, and Bernardino de Sahagun to arrive at a better understanding of the events under consideration.