Following his role in the T4 programme, Brack was one of the men identified as responsible for the gassing of Jews in extermination camps, having conferred with Odilo Globočnik about its use in the practical implementation of the Final Solution.

[1] In 1928, he completed a degree in agriculture at the Technical University of Munich and shortly thereafter began managing the estate attached to his father's sanatorium; he also was a test driver for BMW.

[14] Beyond those reasons, Brack added the ideological components of racial hygiene as grounds for their extermination, atop stressing the importance of the war effort above humanitarian factors.

[15] There were six principal killing centers; these resided at Hartheim, Sonnenstein, Grafeneck, Bernburg, Brandenburg, and Hadamar; most of which, historian Robert Lifton points out, "were in isolated areas and had high walls—some had originally been old castles—so that what happened within could not be readily observed from without.

[22] Not only did the Einsatzgruppen mobile units assigned there kill Jews, but they also gassed Gypsies, people suffering from typhus, Soviet POWs, and the insane; all of whom were led into the vans, murdered, and then driven to nearby woods so their bodies could be placed in mass graves.

Since Brack was transferred to an SS division, his deputy Blankenburg took over responsibility for the task and would "immediately take the necessary measures and get in touch with the chiefs of the main offices of the concentration camps".

[25] When sterilization proved impracticable, this was rejected in favor of exterminating the Jews using poison gas, since the technical apparatus was already in place via T4 to kill unwanted "mentally ill" persons.

[26] With the completion of the T4 euthanasia programme run by Brack, the Nazis dismantled the gas chambers previously used for that endeavor, shipped them east, and reinstalled them at Majdanek, Auschwitz, and Treblinka.

[33] He contested his complicity in mass X-ray sterilizations until confronted by his signature on corresponding documents; meanwhile other administrators—Rudolf Brandt and Wolfram Sievers—testified against Brack, proving links between him, the Führer's Chancellery, and Hitler.