In an answer by Peter, the following statement appears:
An interesting detail is that at that time (1977, probably) apparently the court could refrain from demanding an oath if the defendants agreed. That "Ziffer 5" must since have been removed from §61 of the Code of Criminal Procedure (StPO).
This is based on a film's depiction of the law, so there might be truth, or just artistic license, or ecen a number error, but in general:
What was this §61 StPO Ziffer 5, if it ever existed?
From 1st January 1975 till 31th August 2004 § 61 Nr. 5 StPO read:
Von der Vereidigung kann nach dem Ermessen des Gerichts abgesehen werden […]
- wenn die Staatsanwaltschaft, der Verteidiger und der Angeklagte auf die Vereidigung verzichten.
The statement in the movie is correct. You can find old versions of important German laws on lexetius.com.
Up until 2004, all witnesses had to swear the oath, § 59 StPO aF. So an exception to this rule in § 61 StPO aF was relevant. The exception was introduced as an measure to speed up the process in 1974/75 (draft of the law, p. 47).
A similar rule already existed 1934–1943 as § 61 Nr. 6 StPO. (As this topic was reformed multiple times since 1879 and the paragraph numbers changed, it is not that easy to get an overview of the development of the whole system.)
