Fegefeuer (1971)

Daniel accidentally witnesses a kidnapping on the street. After his report to the police didn't get the attention he had hoped for, he looks for an explanation himself and gets more and more entangled in doubts about his surroundings and his own actions. Through his commitment, he finds himself increasingly exposed to violence and eventually kills a person. During the interrogation by the public prosecutor, he experiences the purgatory of his awakening.