This paper is a review of the development of positions and procedures towards people with mental disorders. From the very beginning of prehistory until today, there have been many changes both in terms of understanding the concept of mental illness, and in the treatment of people who have committed a crime in a state of mental disorder. People with mental disorders have always been one of the most vulnerable groups, and have often been put in an unfair position throughout history. The paper will show how the European Convention for the Protection of Human Rights and Freedoms prohibits torture and inhuman treatment of people with mental disabilities, and how their rights have been violated and the reaction of the Constitutional Court of the Republic of Croatia using legal practice as an example. Other 2 international rules and their regulation and defining the position of people with mental disorders will also be mentioned. The greatest emphasis was placed on the Criminal Code, the Protection of Persons with Disabilities Actand the Criminal Procedure Code, and the novelties introduced in the treatment of people with mental disorders who committed a criminal offense. As the three most important sources, they define the concepts of guilt, incompetence, regulate special treatment of defendants with mental disorders, involuntary placement and treatment at large.