Walter Gerhard Martin Sommer (8 February 1915 – 7 June 1988) was a German SS Hauptscharführer (master sergeant) who served as a guard at the concentration camps of Dachau and Buchenwald.

Sommer, known as the "Hangman of Buchenwald", was considered a depraved sadist who reportedly ordered two Austrian priests, Otto Neururer[1] and Matthias Spanlang,[2] to be crucified upside-down.

[3][4] In 1943, Reichsführer Heinrich Himmler appointed SS judge Georg Konrad Morgen to investigate charges of corruption at the Buchenwald camp.

On occasions, after private late-night torture sessions, Sommer would hide his victims' bodies under his bed until he could dispose of them in the morning.

Among his acts of depravity were beating a German pastor, hanging him naked outside in the winter then throwing buckets of water on him and letting him freeze to death.

In July 1958 in Bayreuth district court in West Germany, he was ultimately convicted of 25 deaths and received a life sentence.