Well, the holocaust of bullets started very early. In a sense, the final solution was, as cynical as it is, by the logostocal challenges of killing all jews by bullets (after there was shooting war going on at the same time) and the practical, and ideological, impossible solution of deporting them. Hence mass extermination camps as the only logical solution. Cynical bastards, all of them.

To get some better feeling, and insihjt, I can only recommend the original film, German, about the Wannsee Conference based on the actual meeting minutes.