6.  The applicant was born in 1977 and is a life-sentenced prisoner. He has been detained in X Prison since 2008. During the relevant period he was detained in the increased surveillance wing of the prison. 7.  In January 2012 the applicant had been relocated from one section of the increased surveillance wing to another. 8.  On 11 February 2012 the applicant entered the cell of a fellow prisoner and stabbed him multiple times in the stomach, back and arms with a scissor blade. The attacked prisoner was taken to hospital following the incident. According to the applicant’s explanation to the prison he had considered it necessary to punish his fellow inmate, as he had allegedly behaved arrogantly towards him. 9.  On 13 February 2012 the prison administration decided to impose additional security measures (täiendavad julgeolekumeetmed) on the applicant. It took into account the stabbing incident of 11 February 2012, the applicant’s history of aggressive behaviour and emotional characteristics (see paragraphs 12–13 below), and the need to ensure the health and safety of all those employed and detained in the prison. The measures entailed placing the applicant in a locked isolation cell (eraldatud lukustatud kamber); restricting his freedom of movement and communication inside the prison; banning him from using the prison’s sports facilities; and handcuffing him whenever he was taken outside of his cell. The decision stated that the measures were to be applied until the grounds for them ceased to exist, but for no longer than six months. It also indicated that the decision had to be served on the applicant. 10.  The applicant lodged a complaint against the decision with the Tartu Administrative Court, but as he had failed to pay the State fee, the court refused to examine it. 11.  On 10 August 2012 the prison administration took two decisions by which it decided to prolong the application of additional security measures. On 9 August 2012 the applicant had been given the possibility to express his opinion about the planned prolongation. The decisions indicated that they had to be served on the applicant. 12.  In the first decision the authorities listed the applicant’s five previous convictions (for, inter alia, theft, hooliganism, acts of violence, fraud, and extortion causing damage to life or health) before he was convicted and sentenced to life imprisonment. They then noted that the applicant had been convicted and given a life sentence in 2001 for the murder of two people and the attempted manslaughter of another person. The authorities also provided a detailed summary of incidents, altogether seventeen, which had occurred in prison between February 2002 and the incident of 11 February 2012 and which involved unlawful activity, disruptive behaviour and insubordination, and repeated violence or the threat of violence on the part of the applicant against the prison officers. They further listed a total of twenty-five prior decisions, taken since 2003, to apply additional security measures to the applicant. 13.  The decisions also referred to a personal risk assessment dated 20 September 2011, which stated that the applicant had a low tolerance to stress and low self-criticism, which was supported by the fact that expressing anger had previously helped him get his way. He blamed others for his problems, and was found to resort to self-harm and injuring others to get what he wanted. 14.  Taking this into account, as well as the fact that on 30 May 2012 the applicant had, in a telephone call to the Ministry of Justice, said that he would be left with no option but to assault a prison officer, the prison authorities held that it would not be possible to discontinue the additional security measures. The fact that the applicant did not have any valid disciplinary punishment at the time the decision was taken was not considered decisive. 15.  By the first decision of 10 August 2012 the following additional security measures were imposed on the applicant:
(i)  placement in a locked isolation cell to better monitor him and prevent contact with other prisoners, towards whom he might become violent;
(ii)  restriction on his freedom of movement and communication inside the prison to prevent contact with other prisoners, whose health he might endanger;
(iii)  a ban on using the prison’s sports facilities, as it was not possible to ensure the restrictions on his freedom of movement and communication while escorting him to these facilities. 16.  The use of handcuffs on the applicant outside of his prison cell was at first not prolonged, but the decision was amended by another decision of the same date which required him to be handcuffed via the hatch on his cell door even before anyone entered. It was considered that he might pose a danger to the prison officers, particularly at the moment when the door was being opened, regardless of whether or not he was to be escorted outside of his cell. 17.  The measures were subject to review within no more than six months after being served on the applicant. 18.  On 30 September 2012 the applicant lodged a complaint with the Tartu Administrative Court, seeking to have the decisions of 10 August 2012 annulled. On 31 January 2013 the court found that the prison authorities had duly considered the applicant’s most recent actions, as well as his overall prior behaviour and personal risk assessment. It found that the application of additional security measures to the applicant had been justified in the interests of other prisoners and the prison officers, and dismissed his complaint. 19.  On 2 March 2013 the applicant lodged an appeal with the Tartu Court of Appeal, requesting that the judgment of the Tartu Administrative Court be quashed and that the decisions of 10 August 2012 be declared unlawful, as it was no longer necessary to annul them as they had ceased to have effect six months after they had been adopted. 20.  On 8 April 2013 the Court of Appeal allowed an application by the applicant to have the annulment proceedings reclassified as proceedings for the determination of unlawfulness. 21.  On 9 January 2014 the Tartu Court of Appeal adopted a decision to join the cases in the second and third sets of court proceedings (see paragraph 29 below). 22.  On 28 February 2014 it dismissed the applicant’s appeal against the judgment of the Administrative Court in the second set of court proceedings. The court noted that the prison had discretion in deciding whether to apply additional security measures and thus the judicial review of such decisions was limited. It found that in the present case the additional security measures had not been applied as a punitive measure, but to prevent possible harm to the life and health of the prison officers and other prisoners. The unpredictable, aggressive and violent behaviour of the applicant had given grounds for a reasonable fear that he might pose such a danger. The Court of Appeal also took a decision regarding the judgment of the Administrative Court of 4 October 2013 in the third set of court proceedings (see paragraph 30 below). 23.  On 1 April 2014 the applicant lodged an appeal on points of law with the Supreme Court against the judgment of the Court of Appeal in the joined cases. On 5 June 2014 it refused to examine the appeal. 24.  On 15 February 2013 the prison administration prolonged the application of additional security measures after giving the applicant the opportunity to express his opinion about the planned prolongation. The decision stated that it had to be served on the applicant. 25.  The decision relied on the already mentioned information (see paragraphs 12 and 16 above) and a new personal risk assessment dated 26 September 2012 (which considered the applicant to be dangerous; it noted that he had a low tolerance to stress and that aggressive behaviour was one of the coping strategies which helped him get his way). In addition, the prison authorities relied on information from the security department that the applicant had attempted to obtain prohibited items through other prisoners so that he could “settle scores”, once the additional security measures were discontinued, with those he had had disagreements with. Based on the above, the security measures were considered necessary to prevent the likely harm the applicant might cause. The same security measures as applied by the decisions of 10 August 2012 were imposed (see paragraphs 15 and 16 above) and were again subject to review within no more than six months after being served on the applicant. 26.  On 7 April 2013 the applicant lodged a complaint with the Tartu Administrative Court, seeking to have the decision of 15 February 2013 annulled. 27.  On 4 October 2013 the court dismissed the complaint. It found that the prison authorities had correctly assessed that the applicant could still be considered unpredictable and dangerous to other prisoners and the prison officers and that the application of security measures – as a preventive step – had been justified. 28.  On 5 November 2013 the applicant lodged an appeal with the Tartu Court of Appeal. 29.  As noted above, on 9 January 2014 it adopted a decision to join the administrative cases in the second and third sets of proceedings (see paragraph 21 above). 30.  On 28 February 2014 it adopted a judgment reversing the judgment of the Tartu Administrative Court of 4 October 2013 in part. The court held that the first-instance court should have found the decision of X Prison of 15 February 2013 unlawful with regard to the period 10 to 14 February 2013, since X Prison had been obliged to review its decisions of 10 August 2012 within no more than six months. It upheld the remainder of the judgment of the Tartu Administrative Court of 4 October 2013. In doing so, the court relied, inter alia, on the information gathered by the prison security department (see paragraph 25 above), which the court examined in closed proceedings as the material was confidential. The court found that the aforementioned information gave X Prison sufficient grounds to believe that, upon the lifting of the additional security measures, the applicant would pose a danger to other prisoners and the prison officers. 31.  On 1 April 2014 the applicant lodged an appeal on points of law against the judgment of the Court of Appeal, but on 5 June 2014 the Supreme Court refused to examine it. 32.  The applicant was kept in different cells over the relevant period, all measuring approximately 9.9 square metres. The Government provided photographs of the relevant cells and a list of the personal items the applicant had in his cells. According to the list, the applicant had had a television set in his cell since 26 July 2012. The applicant was authorised to wear his own clothes. 33.  The applicant was able to have long-term and short-term visits from his next-of-kin. Between 10 August 2012 and 15 August 2013 he was authorised to have thirteen long-term visits (of up to twenty-four hours) to meet his wife and daughters and two short-term visits. On some occasions the visits were cancelled, as the visitors did not attend. During the period concerned he had one meeting with his lawyer. 34.  The applicant had the right to make telephone calls and send letters. He could use the Internet to access legislation and could borrow books from the library. 35.  He had an opportunity to spend one hour daily in the open air and do physical exercises alone in the prison exercise yard, which measured 22.7 square metres. 36.  Between 5 September 2012 and 13 March 2013 the applicant participated in a social reintegration programme entitled “The Right Moment” (focusing on issues such as the mapping of problems, emotions and thoughts; expression and verbalisation of feelings; coping with conflict and tolerating different viewpoints) and between 27 March and 31 July 2013 in the “Anger Management” programme. Both programmes entailed discussions with a psychologist to analyse the covered topics. 37.  Between 28 October 2012 and 4 August 2013 the applicant participated, on an individual basis, in musical activity under the guidance of a recreation leader (huvijuht). According to the information provided by the Government, the activity took place between seven and ten times a month. 38.  The applicant was under constant medical supervision. During the period from November 2006 to August 2016, he turned to the prison medical services with different health issues a total of 1102 times. On 23 August 2016 a psychiatrist issued a certificate stating that, based on a psychological assessment, the applicant did not have an irrational fear of forests (see paragraphs 41 and 58 below). 39.  According to a statement (õiend) issued by the prison on 1 January 2017, between 11 February 2010 and 11 August 2013 the applicant’s cell did not overlook a forest. He was placed in a cell with a forest view on 12 August 2013. 40.  The applicant submitted that he had not been allowed to take part in any social events or recreational activities, and had been totally prevented from associating with other inmates. He added that “during the first few years” (which includes the relevant period in the present case) in a locked isolation cell, he had not been able to use a television set or a radio and that these had been provided only “some two years” after his initial placement in the locked isolation cell. He submitted, however, a reply from X prison dated 10 October 2013, in which the authorities refused to grant him permission to have a radio (as every prison cell already had a built-in radio), but noted that he had been authorised to have a television and thus had been guaranteed sufficient access to information. 41.  In a certificate (tõend) dated 16 August 2013 a psychiatrist asked for the applicant to be relocated to a cell without a forest view. In an opinion dated 23 August 2013 a clinical psychologist discouraged his placement in such cells as they might increase his feeling of loneliness and isolation, particularly at night. 42.  With reference to his musical activity, the applicant submitted a document dated 1 December 2014 in which the X prison authorities explained that in relation to the incident of 11 February 2012, the applicant had not been allowed to take part in musical or art activity, but added that such a right had been granted as of October 2014.