English abstract
In 1852 a forensic scientist called Johann Ludwig Casper documented the case of a group of men who were prosecuted for homosexual offences. Casper used the pseudonym "Count Cajus" for the main defendant. The true identity of "Count Cajus" and the exact circumstances of the case remained a mystery ever since. The riddle has now been solved. The accused was Alfred Count of Maltzan-Wedell (1792-1858). Investigating a charge of perjury, the police seized to a diary in which the Count had meticulously reported all his sexual encounters. On the basis of these reports the police traced more than twenty people in Berlin in 1851/52, thirteen of which were sentenced, some of them long terms of imprisonment. Maltzan himself eventually died in jail.