The work addresses a significant problem for the practice of criminal proceedings: the improperly conducted identification procedure. The long-standing demand from defense attorneys that an improperly conducted identification procedure must lead to the assumption of a prohibition on the use of evidence receives a more in-depth legal-dogmatic justification here for the first time. The work examines the quality standards underlying the identification procedure, its sources of error, its evidential value, and - crucially - its legal classification. Building on this, a problem that has not yet been explicitly named in the law of evidence is discussed: the violation of quality assurance regulations and its legal consequences. The extension of the investigation to the law of evidence in general demonstrates that the assumption.