Who is Willi Mentz from 'the Good Old Days': The Holocaust as Seen by Its Perpetrators and Bystanders and what is their importance?

Mentz was an unskilled laborer and joined the Nazi party in 1932. From 1940 to 1941 he was working as a laborer at several gassing chamber sites without apparent direct involvement in the gassing operations. From mid 1942 to the end of 1943 he was appointed to Treblinka where he organized slave labor. There, his main job was at the so-called 'military hospital' where new arrivals too weak, ill, frail, or injured to walk to the gas chambers were transported. In the 'hospital' they were murdered, partially incinerated, and buried in mass graves. Mentz was the man who shot them, usually using a handgun pointed at the back of the neck at close range. Mentz did not check to see if his victims were still alive, and many are said to have been burned alive. He also served briefly at Sobibor and in Italy. After the war he worked as a milkman until his arrest. He was sentenced to life imprisonment. He is estimated to have personally murdered some thousands of people.