 Lasslo who was originally endorsed as genuine by Schrenck-Notzing was a pickpocket and army deserter.During his séances he confessed to hiding "spirit heads" made from pieces of gauze in Schrenck-Notzing's pocket or in the seat of his armchair.Karl Kraus (pseudo Karl Weber) was a medium that was exposed as a fraud by Professor Hans Thirring in Vienna in 1924.