Kellner, born in Hanover, a husband and father, had been for many years a Berlin police officer (Kriminalschutzmann). Kellner had also been divorced on grounds of adultery. By 1912 Kellner was allowed to dress female while on duty:
"As a police officer, he loves to do investigations in his female persona. This was approved of and the use of female clothing outside of such investigative cases was excused by the fact that he should and wanted to acquire confidence in his behaviour as a woman. Afterwards they gave in to his being a woman, since there was no problems for the police”.
In that year Kellner approached Hirschfeld for an expert opinion so that she could acquire a Transvestitenschein. Hirschfeld and Ernst Burchard wrote a report citing a "case of hermaphroditism … in which the female component decidedly predominates by far". They requested a Transvestitenschein so that Kellner could wear women's clothes all the time, as well as a change of the first name from Emil to Emilie with a corresponding change in the civil register. The Berlin Polizeipräsident approved the Transvestitenschein eight weeks later on 21 October 1912, but rejected the application for the name change because Kellner "could only be recognised as a man based on the official medical report at the time".
By now Kellner had moved to Charlottenburg, a town soon to become a Berlin suburb, to the west of Hirschfeld’s Institut, where she encountered difficulties, especially with employment, because of the discrepancy between her dress and her first name. She was becoming destitute. Two ministry officials reported on this to the Prussian Minister of the Interior at the beginning of 1917. They described Kellner's situation as "quite ambivalent and desperate", an assessment also shared by Charlottenburg's mayor, who "warmly recommends" Kellner's name change. The ministry officials unsuccessfully tried to have Kellner’s first name transcribed in the church register of Kellner's birthplace in Hanover, and requested the Minister to grant the name change as an "exception”. However, the minister found that there was "no sufficient reason" and that a further medical expert opinion had to be obtained first.
6 July 1917, the Ministry of the Interior commissioned another expert opinion from the Royal Medical College, which arrived on 4 October 1917. In contrast to the Hirschfeld-Burchard report, this emphasised Kellner’s male build and found no basis for evaluating her personality as other than male. The Ministry ruled that Kellner could not be recognised as a woman. Perhaps due to the chaos at the end of the War, the notice of rejection was not sent until July 1919.
- Magnus Hirschfeld & Ernst Burchard. “Zur Kasuistik des Verkleidungstriebs”. Ärztliche Sachverständigen-Zeitung, 18, 23, 1912: 477-9.
- Magnus Hirschfeld. “Ein Transvestit”. in Ludwig Levy-Lenz (ed). Sexualkatastrophen: Bilder aus dem modernen Geschlechts- und Eheleben.A H Payne, 1926: 6-18.
- Rainer Herrn. Schnittmuster des Geschlechts: Transvestitismus und Transsexualität in der frühen Sexualwissenschaft. Psychosozial-Verlag, 2005: 91-2.