sentences:  The murders were carried out in pogroms and mass shootings; by a policy of extermination through work in concentration camps; and in gas chambers and gas vans in German extermination camps, chiefly Auschwitz, Bełżec, Chełmno, Majdanek, Sobibór, and Treblinka in occupied Poland.Germany implemented the persecution in stages.Following Adolf Hitler's appointment as Chancellor on 30 January 1933, the regime built a network of concentration camps in Germany for political opponents and those deemed "undesirable", starting with Dachau on 22 March 1933.