Émile Zola, a prominent figure in nineteenth century literature, connects the themes of criminal behaviour and mental complexity in his novel, La Bête Humaine. This work reflects the principles of Naturalism, how heredity and environment can shape human behaviour, particularly through the main character, Jacques Lantier. The aim of this paper is to investigate the complex motivations behind violent conduct and criminal acts from a psychoanalytical perspective. This type of literary analysis demonstrates Zola’s ability to portray the dark dimensions of humanity from a psychological point of view in relation to societal pressures and industrial revolution.