Apart from the obligation to obey the summons, the witness is obliged to testify completely and correctly. Anyone who gives false testimony in court as a witness or as a witness in the course of formal questioning by the criminal police is liable to prosecution under Section 288 of the Criminal Code (StGB) (perjury) and a prison sentence of up to three years.
At the beginning of the examination, the witness must be instructed and admonished to testify correctly and completely. It must also be pointed out to the witness that he or she can bring a trusted person to the questioning. There are also restrictions with regard to the type of questioning. Thus, leading questions – i.e. questions that are posed in a way that influences the witness to give an answer with a predetermined content – are to be avoided in principle and are inadmissible.
In some cases, however, there is an exemption from testifying. For example, persons who are to testify against relatives in the proceedings or victims who are particularly in need of protection are exempt from testifying if they were heard in a protected manner, i.e. not in the presence of the accused (e.g. minors or victims of sexual violence). If the exemption from testifying is not explicitly waived, the entire testimony is null and void. Victims who are particularly worthy of protection have the right to request a protected questioning and are thus given the opportunity not to testify in the main hearing. In this case, the transcript of the protected questioning may be read as an exception. This is special because, apart from a few legal exceptions, there is no provision for the reading of transcripts in the main hearing, but the witnesses are supposed to testify directly in the main hearing.
Furthermore, witnesses have the right to refuse to testify in certain cases. This applies, for example, to witnesses whose testimony would expose relatives to the risk of criminal proceedings or who would make themselves suspected of a criminal offense. Certain professional groups, such as lawyers or psychiatric specialists, are also entitled to refuse to testify as part of their professional duties. If the witness was not informed of his or her right to refuse in good time, that part of the statement to which the right to refuse relates is null and void.
