I Ate His Heart: Interviews with a Cannibal

Driven by her passion for cinema and crime novels, Nathalie von Zelowitz began studying psychology in the late 1980s, intrigued by topics that were considered marginal at the time: serial killers (which were not yet widely discussed; Stéphane Bourgoin's first book, Serial Killers, was published in 1993), sex offenders, sexual perversion, and more. While interning at the Fleury Mrogis Prison in France, she had the opportunity to participate in a national research project on sex offenders after the Van Geloven case shocked the public. Virtually nothing had been published on the subject, and she wrote her master's thesis on rape and her second master's thesis on pedophilia.

She has been a clinical psychologist, specializing in psycho-criminology, for thirty years. She holds a DESS degree in clinical and pathological psychology and a DEA in psychoanalytic studies. She also graduated from the Paris Institute of Criminology well before the existence of university degrees in criminology, which are often overly simplistic. She chose to work in a unique prison in France, the Château-Thierry Penitentiary, which houses "difficult cases" who would be unmanageable in other so-called "normal" establishments due to their behavioral problems or mental illness. Many of these prisoners have made headlines and have even been the subject of true-crime TV shows. At Château-Thierry, she took part in a research project on severe psychopaths. She works there as a clinical psychologist, seconded from the local psychiatric hospital, and intervening at the patient's request, while respecting medical confidentiality. She has been treating some patients for over 10 years. She is also a registered expert psychologist at the Amiens Court of Appeal (the jurisdiction of her workplace), where she is regularly called upon to provide expert system, exempt from professional secrecy.