Delving into the history of cinema in a socialist country through the lens of useful cinema requires looking beyond a centralized administration. Soviet organizations tended to see film as an alluring means of gaining legitimacy, and of competing for resources, labor, and subject matter. This chapter seeks to disentangle such distinct political strata. Rather than conceiving of the image as testimony emerging from a monolithic political structure, it aims to limn the mobile borders between the documentary image as propaganda and as an element of knowledge production subordinated to certain institutions. Focusing on Soviet documentaries that filmed the traces of Nazi crimes committed during the Second World War, it questions the role of organizational interests in shaping knowledge about blood crimes, especially the extermination of the Jews. How does taking the ‘useful dimension’ into account affect our analysis of these documentary films? And conversely, what questions do these instances of forensic evidence raise for the historiography of useful cinema? This shift in perspective illuminates how the global imaginary of Nazi crimes, shaped during the second half of the 20th century, inherited existing traditions of visual knowledge–which in turn demonstrates the broad reach of useful images, beyond the economic and educational contexts most often studied. Soviet cinema is permeated by numerous institutional uses, rooted in the politics of images. Although these atrocity rushes and photos were commissioned, some of them were also included in public distribution and the press, which displaced expert scrutiny within a broader media landscape.