Dylann Roof killed nine people in a Black church in 2015 in order to start a “war” between the white and Black races. This case is used here to develop a psychoanalytic theory of murderous racism, and even genocide. Major concepts from Freud (self-preservation, hatred, narcissism, life and death drives, delusion), Klein (projective identification), and Bion (psychotic and nonpsychotic parts of the personality) are employed. Particular attention is given to the hearing to determine Roof's capacity to represent himself after he dismissed his lawyers, who wanted to use an insanity defense to avoid the death penalty. This hearing was confronted with an undecidable dilemma, which led to legal cooperation with Roof's suicidal impulses. The deconstructive approach to undecidability, and its use in questions of law, especially as concerns the relation between psychoanalysis and the death penalty, leads to tentative recommendations for the prevention of racist murder.