An excellent question, and one that has a surprisingly easy answer. The Dream Police were not formed as an actual organization until 1979 in Rockford, IL.

As Hitler had died some 20 years earlier in the town of San Ramón de la Nueva Orán, Argentina, at the climax of the so-called "War of the Paperclips", it was clearly beyond the Dream Police's purview.

When asked about this during an interview, Commissioner Zander's reply was "Ain't that a shame?", while Inspector B.E. Carlos just drummed his fingers on his desk.