On 23 August 1932, more than a year before the end of his university studies in Giessen and five months prior to the Nazi takeover of power in Germany, Alfred Filbert joined the SS, which was still officially a sub-organisation of the SA (Sturmabteilung, i.e. Storm Detachment), in Worms. His SS identity card carried the number 44,552. Only days after joining the SS, Filbert also joined the National Socialist German Workers’ Party (Nationalsozialistische Deutsche Arbeiterpartei, or NSDAP) in Worms. His NSDAP membership number was 1,321,414. It is tempting to surmise that Filbert may have been one of the 30,000 people who attended Adolf Hitler's speech of 12 June in the Wormatia Stadium on Alzeyer Straße.

According to Filbert's SS certificate of service (Dienstleisstungszeugnis) from 15 December 1934:

During the period in question, from August 1932 to December 1934, Filbert belonged to the SS-Sturm 4/II/33, later renamed the SS-Sturm 8/33. A Sturm, literally meaning ‘storm’ was a sub-unit of the SS corresponding to a company in the regular army and contained between 70 and 120 members. On Shrove Tuesday (28 February) 1933, Filbert was ‘in the front line’ during the ‘heavy fighting’ in Worms, though he was incapacitated from 23 March to mid-May of the same year by a serious case of liver poisoning. In view of the date on which Filbert's incapacitation began, it is tempting to speculate that this may have been caused by excessive alcohol consumption in celebrating the passing of the Enabling Act (Ermächtigungsgesetz) on 23 March. The Enabling Act allowed the German government under Hitler to enact legislation without the participation of the German parliament, the Reichstag. Filbert's involvement in the ‘heavy fighting’ in Worms on Shrove Tuesday 1933 provided him with an opportunity to ‘distinguish’ himself within the Nazi Movement by engaging in (pre-war) physical violence.