8 Ι. – LEGAL FRAMEWORK AND OPERATION OF THE NATIONAL PREVENTIVE MECHANISM T he Optional Protocol to the Convention against Torture and Other Cruel, Inhuman and Degrading Treatment or Punishment (OPCAT) is an international convention on human rights, which was adopted by the General Assembly of the United Nations in 2002 and came into force in 2006. The common denominator was the consensus and the common understanding of the member states of the international community that the efforts associated with combating the ill-treatment of persons who are deprived of their liberty, and are therefore in an especially vulnerable position, should focus on prevention. In this framework, a broader definition of the meaning of torture was adopted, according to which, torture is not merely the systematic causing of pain but also all inhuman and degrading treatment that debases humanity. The use of torture offends human dignity and aims at eradicating the victim’s sense of self. Apart from being a criminal offence, under both national and international law, it is a position contrary to human civilisation. Facilities such as prisons, migrant detention centres, psychiatric institutions, police cells, etc., are danger spots for human dignity. Greece ratified OPCAT with Law 4228/2014, transposing it into national law with increased formal power. Article 2 of the above law designates the Greek Ombudsman as the “National Preventive Mechanism against Torture”. The mission of the National Preventive Mechanism (hereinafter NPM) includes regular investigation of the treatment of persons deprived of their liberty, submission of respective improvement recommendations to the competent authorities and submission of proposals and observations regarding existing legislation or draft laws. Article 4 of Law 4228/2014 stipulates that the NPM shall visit all detention facilities, public or private, with or without prior notification to the competent authorities. Such facilities are prisons, police station cells, psychiatric institutions, places of administrative detention of third-country nationals, welfare institutions, etc. In fact, in line with international practices, these visits may be carried out on non-business days or even at night. NPM inspections include the collection of data using any available means, such as, indicatively, visiting all areas of detention facilities, interviewing persons and taking photographs.