On November 16, 1980, the Marxist philosopher Louis Althusser strangled his wife in their Parisian apartment, in a period when she was thinking of leaving him. What do we know about Hélène Legotien today? Almost nothing, except that she was murdered by her illustrious spouse. In a sense, Althusser killed her twice, first, by his own hands and second, by dominating the public space to talk about himself. What then is the political significance of this femicide and the discourse about it which has taken shape in the public space? Delving into the writings of the murderer and his allies in the French intelligentsia, Killer Althusser reasserts the patriarchal violence of the murder, masculine solidarity, and the complacency of a cultural elite.