“In Mauthausen existed several treatments of prisoners, amongst them the ‘action K or Kugel’ (Bullet action). Upon the arrival of transports, prisoners with the mention ‘K’ were not registered, and received no numbers, and their names remained unknown except to the officials of the ‘Politische Abteilung.’ (Lt. Veith had the opportunity of hearing upon the arrival of a transport the following conversation between the Untersturmführer Streitwieser and chief of the convoy: ‘How many prisoners?’ ’15 but two K.’ ‘Well, that makes 13’).
The prisoners were taken directly to the prison, where they were unclothed and taken to the ‘Bathroom.’ This bathroom in the cellars of the prison building near the crematory was specially designed for execution (shooting and gassing). The shooting took place by means of a measuring apparatus. The prisoners being backed twoards a metrical measure with an automatic contraption releasing a bullet in his neck as soon as the moving plank determining his height touched the top of his head.
If a transport consisted of too many ‘K’ prisoners, instead of losing time for the measurement they were exterminated by gas, laid on to the bathrooms instead of water.”
The Trial of German Major War Criminals, Volume III. London: His Majesty’s Stationery Office, 1946. P. 206