February 18 (from indictment)
On February 18, 1943, he [Hans Scholl] and his sister also scattered additional inflammatory leaflets. On this occasion, he was observed by the witness Schmied (sic) and was apprehended. [Note 1] …
The accused Sophia Scholl likewise participated in the production and distribution of the ‘Student’ leaflets. She accompanied her brother to the university, was observed scattering the leaflets, and was apprehended along with him.
Note 1: Bolded in original. This was crucial to the indictment.
Source: February 21, 1943 indictment