The book contains answers to the most common questions arising in connection with the detention of citizens by law enforcement officers and the further initiation of administrative or criminal cases, the involvement of suspects and accused as witnesses. In a concise and accessible form, professional advice and recommendations of experienced lawyers are presented, relating mainly to the pre-trial stage of the criminal process. The publication will be useful not only to those who are already under administrative proceedings or criminal prosecution, including those in custody, but also to a wider audience, since it gives an idea of ​ ​ the rights and obligations of witnesses, suspects, accused and defenders in criminal cases.