This study aims to determine the factors associated with the victim’s death in sadistic sexual crimes. Specifically, this article examined whether the lethal outcome is more likely to be associated with an escalation of violence during the crime-commission process, an instrumental motivation, or the manifestation of specific sadistic fantasies. We used a database including 735 cases of sadistic sexual assaults. Among this sample, 100 sadistic sexual assaults ended with a lethal outcome. Bivariate analyses, logistic regression, and neural network models were used to identify how the different factors predicted the lethal outcome of sadistic crimes. Our results show that the expression of sadistic behaviors associated with torture and/or bodily punishment plays a fundamental role in the lethal outcome of sadistic sexual crimes. Theoretical and practical implications are discussed.