Artur Nebe, head of Einsatzgruppe B and of Department V (the Criminal Police) at the Reich Security Main Office, turned first to his his deputy, a man named Werner, and ordered him to have a chemist from the Criminal Technology Institute, Dr. Albert Widmann, come to Minsk with esplosives and metal hoses. An attempt to blow up a bunker with mentally ill patients inside had been a failure, so it was decided to use exhaust fumes in the experiment to be conducted at the asylum at Moghilev, east of Minsk. Dr. Widmann described the preparations for this operation and its progress:

During the afternoon Nebe had the window bricked in, leaving two openings for the gas hose....When we arrived, one of the hoses that I had brought was connected. It was fixed onto the exgaust of a touring car....Pieces of piping stuck out of the holes made in the wall, onto which the hose could easily be fitted....After five minutes Nebe came out and said that nothing appeared to have happened. After eight minutes he had been unable to detect any result and asked what should be done next. Nebe and I came to the conclusion that the car was not powerful enough. So Nebe had the second hose fitted onto a transport vehicle belonging to the regular police. It then took only another few minutes before the people were unconscious. Both vehicles were left running for about another ten minutes.