One of the grounds for retrial in favour of the defendant is the discovery that a witness or expert witness, who has been heard under oath, has intentionally or negligently given false testimony or cast a vote in a manner that could influence the judgment to the detriment of the defendant. (CMK 311/1-b)
For false testimony or expert opinion to be considered a reason for retrial, it must have affected the verdict. In practice, if interpreters, who are accepted as experts, intentionally or negligently translate statements or documents contrary to the truth (TCK 276/2.md.), and this affects the judgement, then interpreters must also be accepted (by analogy) under CMK 311/1-b. If it is understood that false testimony or an expert report or untrue translation did not affect the ruling, and that the court did not base its ruling on them, then it is not possible to retry the case on these grounds. Since the law refers to ‘witnesses or experts heard under oath,’ the statements of witnesses heard without oath (CMK 50, 51) do not constitute grounds for retrial. If the statement of a witness heard without oath has affected the ruling, this situation should be considered as a new event under Article 311/1-e.
False testimony or expert opinion must be established by a final judgment. This is because giving false testimony or expert opinion with intent or negligence against the convicted person is defined as a crime under Articles 272 and 276 of the Turkish Criminal Code (TCK), and for this to be grounds for retrial, it must be established by a final judgment or it must be understood that no judgment could be rendered on this matter for reasons other than insufficient evidence. If the person has died before a ruling is made for false testimony or expert testimony and no ruling can be made, or if they have been acquitted due to reasonable doubt, this situation may be considered a new event and the trial may be reopened.