The term Black criminality refers to the systemic conflation of Blackness with crime and vice. Muhammad emphasizes the foundational role that ideas of Black criminality played in race relations of the urban North, and how the ideology morphed through the late 19th to mid-20th centuries. Black criminality began with conservative white supremacists seeking to obtain irrefutable evidence of Black inferiority. However, the ideology grew so pervasive that racial liberals—including some Black scholars—encouraged the linking of race to crime through means than white supremacists.

The ideology painting Black Americans as criminals fueled many instances of racial violence and riots that occurred throughout the 1910s. This era of American history saw precisely how dangerous of a force Black criminality was. The ideology was institutionalized in the 1930s when the United States launched a major reform of its criminal justice system, overturning many old practices, including the notations of immigrant status and racial notations for white crimes. Yet, racial notation for Black crimes continued through this period of reform. Here, Muhammad argues that the state effectively erased white crime while emphasizing Black crime, placing the ideology of Black criminality within the modern foundations of American justice. Thus, Black criminality’s history is crucial to understanding both the past and present.