Laurence Rees makes the point that early concentration camps like Dachau (built in 1933) and Sachsenhausen (1936) should not be confused with the later extermination camps such as Treblinka, whose sole function was murder. JWs had little experience of the later death camps, the experiences they related were in relation to the concentration camps. Rees states that Dachau and other concentration camps were well known worldwide and the atrocities were publicised from the start.
The Holocaust: A New History (2017), Laurence Rees p.74.
But while Beimler was justified in calling Dachau a 'murder' camp, given that a small number of prisoners were killed there during this period, these concentration camps should not be confused with later extermination camps - like Treblinka - whose only function was to kill. Appalling as the regime was at Dachau before the war, the majority of those who were sent to the camp at this time survived the experience.