The work was awarded the University Prize by the Munich Bar Association at the University of Passau. Through three exemplary cases from the field of criminal defense, the author explores the question of whether, in certain situations, witnesses have the right to remain silent in criminal proceedings, a right that is not codified in the Code of Criminal Procedure or in ancillary laws. The author examines witnesses who are supposed to report either on the content of discussions with their former criminal defense attorneys or on the content of conversations with their lawyers or so-called witness assistants. The solutions in the paper are developed based on existing approaches in case law and literature. The direct application of constitutional law is rejected in this context. Instead, a solution is sought within statutory law (§ 68 a StPO), even in cases where, for example, the criminal defense attorney may have committed an offense.