After arriving in Poland the group spent three days at the former Auschwitz concentration camp site, and another at the former Majdanek concentration camp. At these, they filmed Leuchter illicitly collecting what he regarded to be forensic quality samples of materialsfrom the wreckage of the former gas extermination facilities, while his wife and the translator acted as lookouts. Drawings of where the samples were taken from, the film footage of their physical collection and Leuchter's notebook detailing the work were surrendered to the trial court as evidence. Leuchter claimed that his conclusions were based on his expert knowledge of gas chamber operation, his visual inspection of what remained of the structures at Auschwitz, and original drawings and blueprints of some of the facilities. He said that the blueprints had been given to him by Auschwitz Museum officials.