Erich Gustav Willie Lachmann (6 November 1909 – 23 January 1972) was a police auxiliary and SS-Scharführer (Sergeant) who participated in the "Operation Reinhard" in the Sobibor extermination camp. Lachmann was born in Liegnitz on November 6, 1909. He began his career as a policeman. In the so-called "Sobibor Trial" in Hagen, which lasted from to , he was accused of participating in the mass murder of approximately 150,000 Jews. The court found Lachmann to be mentally incompetent and he was acquitted because of "putative duress".