The principle of openness, as one of the foremost principles of criminal proceedings, is realised above all during the main trial. The amendment act of law to the code of criminal procedure issued on 10 June 2016 introduced model changes in this regard. The article is devoted to a discussion of mainly these changes in the context of their consistency with the Constitution. The first change has to do with the fact that the public prosecutor has the right to express his or her objection toward the holding of a trial in camera, while such an objection is binding for the court. This regulation is a source of reservations of constitutional nature, for it violates the constitutional right to a fair adjudication of a case by the court. The second ...