In the 1980s and 1990s, historian Peter Black worked for the US Department of Justice Office of Special Investigations, as part of a team tracking and prosecuting suspected war criminals. Black later served as the Senior Historian at the United States Holocaust Memorial Museum.
What happened was, as we got the cases, we began to investigate them as a historian would investigate them, and in order to ... they were like little biographies. And I of course had written a biography for my dissertation, and it was a biography of an individual, the chief of the Nazi Security Police (SD), Ernest Kaltenbrunner, who had left very little of himself behind, and I had to go into this biography by dealing with the organizations to which he belonged, and by dealing with the individuals with whom he associated, and in many ways OSI on a much lower level dealt with that type of investigative process. And so what the historians started to do -- and now again my former colleague David Marwell and I talked about this quite a bit when we were both at OSI as young historians. What we started to do was to gather documentation, primary source documentation, we understood as historians what kinds of documentation bore what weight of reliability. We gathered documentation on the institutions that were relevant to the charges in the complaint. We would gather information on the individual but would also gather information on the comrades of the individuals. And this served two purposes. On the one hand we wanted to talk to those comrades if they were still alive, because they could tell us things that the victims of the defendant couldn't. And they could also tell us about the daily routine, which information the defendant was not going to give us, we couldn't get it from any other source, other than the hints that were left in the documentation. And for a second reason, is that the personnel material, and the administrative material of the organization that these people belonged to, whether it was a concentration camp or a security police unit or an auxiliary police unit, gave us a fairly accurate and fairly reliable picture of what the daily life of this defendant was, so that an expert witness could get up in front of a judge and say with complete conviction that on a daily basis, on a normal day so and so rotated into these particular guard assignments, and this was part of his daily duty, now maybe he didn't do it on this day or that day, but if you take a period of time, whether it was a week or three months, he was doing it in this order at least sometime, and this was part of the daily routine, the standard operating procedure of this particular unit in this particular place.