This article provides an in-depth description of the case of Michel Fourniret (MF), a French serial killer who, with his wife Monique Olivier (MO), confessed to kidnapping, raping, and murdering at least nine girls during the 1980s and 1990s. Using information from writers, witnesses, trial experts, and regarding current forensic literature, we utilize this case to discuss sexual homicide from both the forensic and neuropsychiatric perspectives. Interview, psychometric, and forensic data from the trial were used to explain and shed light on MF's and MO's personalities and psychosexual proclivities. In the final section, we propose and discuss several theories and specific areas of potential exploration that, in light of the murder couple case story, may prove fruitful in the study of violent attachment and murder pacts. (Published Abstract)