The purpose of this essay is to examine the discourses that surrounded the life of Leon Czolgosz, the assassin of President William McKinley. The gaps in Czolgosz’s life, his peculiar silences, his poor health and the ambiguity and thinness of his confession, rather than taken as instances of mental and physical distress, have, instead, been understood as signs of a revolutionary anarchistic assassin. Czolgosz is an expression of a cultural tradition in somatic form. I argue that the discursive construction of criminality, already present in the late nineteenth century within the medical and human sciences, is what shaped Czolgosz’s life story.