On those grounds, the Court (Grand Chamber) hereby rules:
Article 1(3) of Council Framework Decision 2002/584/JHA of 13 June 2002 on the European arrest warrant and the surrender procedures between Member States, as amended by Council Framework Decision 2009/299/JHA of 26 February 2009, read in conjunction with Article 4 of the Charter of Fundamental Rights of the European Union, must be interpreted as meaning that when the executing judicial authority has objective, reliable, specific and properly updated information showing there to be systemic or generalised deficiencies in the conditions of detention in the prisons of the issuing Member State, it must, for the purpose of assessing whether there are substantial grounds for believing that, following the surrender to the issuing Member State of the person subject to a European arrest warrant, that person will run a real risk of being subjected to inhuman or degrading treatment within the meaning of Article 4 of the Charter, take account of all the relevant physical aspects of the conditions of detention in the prison in which it is actually intended that that person will be detained, such as the personal space available to each detainee in a cell in that prison, sanitary conditions and the extent of the detainee’s freedom of movement within the prison. That assessment is not limited to the review of obvious inadequacies. For the purposes of that assessment, the executing judicial authority must request from the issuing judicial authority the information that it deems necessary and must rely, in principle, on the assurances given by the issuing judicial authority, in the absence of any specific indications that the conditions of detention infringe Article 4 of the Charter of Fundamental Rights.
As regards, in particular, the personal space available to each detainee, the executing judicial authority must, in the absence, currently, of minimum standards in that respect under EU law, take account of the minimum requirements under Article 3 of the Convention for the Protection of Human Rights and Fundamental Freedoms, signed at Rome on 4 November 1950, as interpreted by the European Court of Human Rights. Although, in calculating that available space, the area occupied by sanitary facilities should not be taken into account, the calculation should include space occupied by furniture. Detainees must, however, still have the possibility of moving around normally within the cell.
The executing judicial authority cannot rule out the existence of a real risk of inhuman or degrading treatment merely because the person concerned has, in the issuing Member State, a legal remedy enabling that person to challenge the conditions of his detention or because there are, in the issuing Member State, legislative or structural measures that are intended to reinforce the monitoring of detention conditions.
A finding, by the executing judicial authority, that there are substantial grounds for believing that, following the surrender of the person concerned to the issuing Member State, that person will run such a risk, because of the conditions of detention prevailing in the prison in which it is actually intended that he will be detained, cannot be weighed, for the purposes of deciding on that surrender, against considerations relating to the efficacy of judicial cooperation in criminal matters and to the principles of mutual trust and recognition.
1, 4-8, 35-36, 41, 55-56, 58, 62, 68-69, 77, 79-86