5.  The applicant was born in 1952. At the time of lodging his application, he was detained in Berlin Tegel Prison. He now lives in Berlin. 6.  On 1 October 1998 the Berlin Regional Court convicted the applicant of dangerous assault. It sentenced him to six years and six months’ imprisonment and ordered his preventive detention under Article 66 § 1 of the Criminal Code (see paragraph 36 below). The court found that the applicant had stalked his former girlfriend, terrorised her and her family with telephone calls, sudden appearances and threats against their life and limb, had finally waylaid his former girlfriend in front of her workplace and had stabbed her twice in the neck with a pair of scissors with the intention of killing her. He had stopped short of stabbing his victim to death. Endorsing the findings psychiatric expert A. had set out in his report, the court was of the view that the applicant had acted with diminished criminal responsibility as he had been in a state of affective excitement and suffered from a neurasthenic syndrome at the time of the offence. The court found that the applicant, who had previously been convicted in 1975, 1977, 1981, 1983 and 1988 of comparable offences including dangerous and sexual assault and rape, committed mostly against former girlfriends at the end of their relationship with him, had a propensity to commit serious violent offences and was dangerous to the public. 7.  The applicant served his full term of imprisonment, which ended on 27 February 2005, essentially in Berlin Tegel Prison. 8.  The applicant was not released at the end of his prison sentence but remained in factual preventive detention without a formal decision of the competent courts for the execution of the preventive detention order under Article 67c of the Criminal Code (see paragraph 36 below), because the proceedings were delayed. 9.  On 15 June 2007 the Berlin Court of Appeal decided that the applicant’s further preventive detention without a court decision ordering its execution was unlawful, and ordered its interruption. The applicant was released on that day. 10.  On 9 July 2007 the Berlin Regional Court ordered the execution of the applicant’s preventive detention in accordance with Article 67c § 1 of the Criminal Code as it was not reasonable to expect that the applicant would commit no further unlawful acts if released. It took note, in this context, of the view expressed by psychotherapy expert B., who had considered that the applicant’s impulsive and offensive behaviour in the hearings in June 2007 had confirmed the finding in his report dated 15 September 2005 that the applicant was still dangerous to the public. 11.  The applicant appealed against the decision. He remained at liberty while the appeal was pending. 12.  While he was at liberty, he found a flat and a job and voluntarily started psychotherapy treatment with a female psychologist, So. He regularly attended weekly therapy sessions with So. and did not commit any criminal offences while at liberty. 13.  On 27 May 2008 the Berlin Court of Appeal upheld the Berlin Regional Court’s decision. Just like the Regional Court, it based its decision on a medical expert opinion drawn up previously by psychotherapy expert B. and psychologist S. Expert B. had examined the applicant on four occasions between February and September 2005. S. had performed psychological tests with the applicant in March 2005. Both experts had issued their common written medical report on 15 September 2005 and had supplemented it with a further medical statement answering the questions of counsel representing the applicant on 20 April 2006. The original report was moreover based on the examination of the applicant’s prison files and a large number of investigation files, as well as on an interview with one of his fellow prison inmates. 14.  In their written report, the experts came to the conclusion that the applicant suffered from a narcissistic and antisocial personality disorder. They were of the view that there was a very high risk that the applicant would reoffend because of his personality structure and could be expected to commit serious criminal offences mainly directed against potential female victims’ physical and sexual integrity. The applicant had continually committed new offences while on probation, so that his probation had been revoked on five occasions. He had mostly committed crimes against the physical and sexual integrity of women and usually at the end of his relationships, when he had been unable to accept that his girlfriend had left him. Therapeutic treatment had not been successful so far. 15.  The court endorsed the findings of the psychiatric experts. It ruled that although the applicant had not committed any offences during his year at liberty, and although he had voluntarily and regularly undergone psychological treatment during that year, there was no reason to believe that he would abstain from reoffending. In the past the applicant had already abstained from committing further offences for longer periods. Situations similar to those in which the applicant had previously committed offences, especially against the physical and sexual integrity of his female partners, at the end of relationships, were likely to arise and to escalate again just as in the past. 16.  On 30 May 2008 the applicant returned voluntarily to Berlin Tegel Prison for the continuation of his preventive detention. 17.  On 2 September 2008 the Federal Constitutional Court declined to consider the constitutional complaint lodged by the applicant against the Regional Court’s and the Court of Appeal’s decision on the execution of the preventive detention order (file no. 2 BvR 1612/08). 18.  On 20 December 2012 an application (no. 12132/09) lodged with this Court in this context was declared inadmissible by a Single Judge in a procedure pursuant to Article 27 of the Convention. 19.  On 12 October 2009 the Berlin Regional Court decided in its first periodic review proceedings, in accordance with Articles 67d § 2 and 67e §§ 1 and 2 of the Criminal Code in their then relevant version (see paragraph 36 below), that the applicant’s preventive detention was to continue. It found that it was not reasonable to expect the applicant to commit no further unlawful acts on his release. 20.  The court heard the prison authorities which, in their written statement of 6 March 2009, submitted that the applicant was not willing to work on his problems and refused any therapeutic treatment in the detention centre. The court also heard the applicant on 25 September 2009. It further based its decision to extend the applicant’s preventive detention on the opinion of psychotherapy expert B. and psychologist S. of 15 September 2005, supplemented on 20 April 2006 (see paragraph 13 above). It had regard to the fact that the applicant had been convicted fifteen times since 1971, including ten convictions for violent crimes. 21.  The Regional Court further dismissed the applicant’s request for a new psychiatric expert opinion. It found that Article 454 § 2, read in conjunction with Article 463 § 3 of the Code of Criminal Procedure (see paragraph 37 below), only required a new psychiatric expert report as a basis for a periodic review decision if the court was considering releasing a detainee from preventive detention on probation, in order to ensure that he was no longer a danger to the public. The court held that, in accordance with the case-law of the Federal Constitutional Court (see decision of 3 February 2003, file no. 2 BvR 1512/02) and of the Constitutional Court of Berlin (see decision of 4 March 2009, file no. VerfGH 104/07) it was otherwise within the discretion of the court assessing the need to extend the preventive detention order to decide whether a new expert opinion was necessary. As a rule, an expert opinion would be necessary if the detainee suffered from psychiatric anomalies that demanded a psychiatric expert’s assessment in order to be able to predict the danger he represented for the public. Otherwise, a new psychiatric expert report was generally not necessary unless special new circumstances demanded a new examination of the detainee. 22.  The court found that, in accordance with the legal standards described, there was no necessity to seek a new expert opinion. It referred to the arguments given in the Court of Appeal’s decision of 27 May 2008, adding that there had been no significant changes since then. The applicant had refused to undergo therapeutic treatment within the detention centre since he had been returned to preventive detention. His age of 57 years did not warrant a different conclusion as regards the danger he represented in the circumstances of his case. The written expert opinion of B. and S. of 15 September 2005, supplemented on 20 April 2006 and explained by B. at two hearings, lasting a total of six hours, before the Regional Court in June 2007, was therefore still recent enough. 23.  The court was, however, of the view that the applicant should be allowed to continue his therapy with the external psychologist So., which he had not been authorised to pursue since his renewed preventive detention. The prison authorities should allow him to continue and organise escorted short-term leave for therapy sessions with his psychologist outside the detention centre. 24.  On 24 March 2010 the Berlin Court of Appeal dismissed the applicant’s appeal. The court considered that releasing the applicant on probation on the condition that he underwent therapeutic treatment outside the detention centre would be irresponsible. There were no convincing and verifiable indications that the applicant had tackled his offences or the flaws in his character that had led to them. The year he had spent at liberty during the interruption of his preventive detention did not prove otherwise, although he had not reoffended during that period of time. The applicant had already abstained from committing offences for longer periods of time in the past, but had nevertheless repeatedly committed serious offences against the physical integrity of his female partners when they had ended their relationship with him. Having regard also to the personality disorders leading to his dangerousness, the period of one year at liberty was therefore too short to prove that the applicant was no longer dangerous. In this regard, the court referred to the reasoning in its decision of 27 May 2008 and the expert opinion of B. and S. on which that decision was based (see paragraphs 13-15 above). 25.  The court further recognised that the applicant had voluntarily undergone psychological treatment once per week with the psychologist So. while at liberty. However, it considered that there was no proof of the success of this treatment. Instead, the impulsive and offensive way in which the applicant treated other people, notably those working in the detention centre, showed that his attitude and his character had not changed and that he was still unwilling to cooperate. 26.  Moreover the court found that, although the prison authorities had, without giving proper reasons, refused to grant the applicant escorted short‑term leave from prison, especially short-term leave for the purpose of meeting his external therapist So., such deficiencies in the execution of the preventive detention did not justify the applicant’s release. The court recognised that prison leave was necessary in order to enable the applicant, in the long run, to prove his capacity to live at liberty again without committing further offences. However, the court was of the view that, even if the applicant had been granted the necessary leave since his readmission into preventive detention, the period passed since then would have been too short to prove that he was no longer dangerous. Therefore, the continuation of the applicant’s detention was not yet excessive. 27.  The Court of Appeal was moreover of the view that the Regional Court’s decision not to commission a new medical expert opinion was lawful and did not breach its duty to establish the relevant facts. As explained above, a new psychiatric expert would not be confronted with a significantly different situation to the one B. and S. had found when they prepared their expert report. The applicant’s refusal to cooperate and to accept further psychological treatment within the detention centre showed that the therapy with So. had not significantly changed his character and behaviour. 28.  On 16 June 2010 the Federal Constitutional Court declined to consider the applicant’s constitutional complaint against the decisions of the Berlin Regional Court and the Berlin Court of Appeal, in which the applicant had alleged breaches of his constitutional rights to liberty and to a fair trial (file no. 2 BvR 903/10). 1.  The proceedings concerning the applicant’s request to be granted escorted short-term leave for external psychological treatment 29.  On 24 March 2010, upon the applicant’s appeal, the Berlin Court of Appeal, in a separate decision, quashed the prison authorities’ and the Regional Court’s decision refusing the applicant short-term leave to continue his psychotherapy treatment with So. as from October 2008. The court ordered the prison authorities to grant the applicant escorted short‑term leave at least every second week in order to undergo further psychotherapy treatment with the external psychologist, So. 30.  The applicant was enabled to attend psychotherapy sessions with So. until his relationship of trust with the psychologist came to an end in September/October 2010. On 9 December 2010 the Berlin prison authorities thereupon suspended the applicant’s prison leave, finding that the applicant had repeatedly threatened So. On 29 April 2011 the Berlin Court of Appeal upheld that decision. It found that there was a risk that the applicant would use the prison leave to commit further offences, seeing that his dispute with So. resembled the situation arising in the applicant’s past relationships with women prior to his committing serious offences against them. 31.  The applicant’s subsequent requests to be granted access to treatment with the external psychiatric expert Dr P. in a Berlin clinic were turned down by the prison authorities, confirmed by the Regional Court. The Berlin Court of Appeal quashed these decisions on 3 November 2011 and 4 May 2012 and ordered the prison authorities to reconsider the applicant’s requests in view of the court’s findings. In its decision of 4 May 2012 the Court of Appeal found that, as it had explained in its decision of 24 March 2010, the applicant could not be obliged to undergo therapy in prison. The applicant resumed external psychotherapy in September 2012. 32.  On 22 May 2012 the Berlin Regional Court issued its decision in the fresh periodic review proceedings. It held that the execution of the preventive detention was to be suspended on probation as from 20 November 2013, ordered the applicant’s probationary supervision for five years and ruled, inter alia, that the applicant was to avoid any contact with his former external psychologist So. and her family, as he had started to stalk her and threaten her with e-mails and telephone calls. 33.  The court, endorsing the findings in a new external psychiatric expert opinion issued by P., held that although the probability that the applicant would reoffend at liberty was still high, it would be possible to release the applicant on probation after a preliminary period of about one year if the pre-operational phase was mastered by the applicant without further problems. As the prison authorities had ignored and boycotted the court’s orders to grant the applicant access to external psychological treatment for years in a way the court had never seen before and which it found to be unconstitutional, the applicant’s interest in being at liberty now outweighed the public interest. 34.  On 12 October 2012 the Court of Appeal upheld that decision on appeal. It found that the applicant’s immediate release was not to be ordered owing to the danger he represented. Referring to a report drawn up by expert D. in 2010, it stressed in that context that the fact that the applicant had not reoffended while at liberty in 2007/2008 was not conclusive of his not representing a danger. The applicant had previously committed offences in the context of relationships with women. However, he had not had such a relationship during the time he was at liberty. Furthermore, he did not have a right to choose freely his therapist. 35.  The applicant was released on parole on 20 November 2013.