5.  The applicants were born in 1939 and 1933 respectively and live in Sofia. 6.  They are the parents of Mr Ivaylo Zashev, who was shot and killed by people trying to rob him in his aunt’s house in the village of Stavertsi, in the Pleven region, in the late hours of 3 February or the early hours of 4 February 1997. 7.  In the morning of 3 February 1997 Mr Ivaylo Zashev and his brother, Mr Valeri Zashev, both of whom had come to Stavertsi for a business venture, went to a neighbouring village to see if they could buy cattle. Later that day they went to Pleven to exchange 2,000 German marks and 1,000 United States dollars. They were also carrying 200,000 old Bulgarian levs. They did not exchange the money and in the evening went back to Stavertsi. At about 10.45 p.m. they went to sleep. Their aunt, Ms T.L., was sleeping in the adjoining room. 8.  Around midnight the two brothers woke up and saw in the room three men wearing masks and gloves. One of them was carrying a shotgun, the other a metal pipe, and the third was unarmed. The two armed assailants started fighting with Mr Ivaylo Zashev and Mr Valeri Zashev, while the unarmed one sifted through the items in the room. While the assailant with the pipe was hitting Mr Valeri Zashev, Mr Ivaylo Zashev was trying to protect himself with a chair from the one with the shotgun. The assailants ordered the brothers to hand over the money they had. Mr Ivaylo Zashev replied that it was in his trousers and, while the assailants were checking them, he managed secretly to slip the bag with the money under his bed. At that point Ms T.L. entered the room. The assailants were startled. One of them told the one with the shotgun to fire. He pulled the trigger, but the gun jammed. However, after that he fired two shots, the second of which hit Mr Ivaylo Zashev in the chest and pierced his heart and lungs; about a minute later he died. The assailants pushed Ms T.L. to the ground, face down. Then they went out of the house despite Mr Valeri Zashev’s efforts to stop them. They reached their car, which was parked nearby, and left the village. 9.  Approximately two hours after the events, at 1.55 a.m. on 4 February 1997, an investigator from the Pleven Investigation Service inspected the crime scene with two police officers, an expert and a forensic doctor. He found and seized a hunting bullet, a hunting cartridge case, a pistol cartridge case, four rubber bullets and two hunting‑bullet caps. 10.  Later that day the investigator asked an expert to express an opinion on the extent of the injuries suffered by Mr Valeri Zashev and Ms T.L. and the manner in which they had been inflicted. He also asked a clinic in Pleven to clarify the exact cause of Mr Ivaylo Zashev’s death, the distance and the position from which the shot had been fired, and the relative positions of the victim and the shooter. 11.  Between 12 February and the end of March 1997 the investigator interviewed Mr Valeri Zashev, Ms T.L. and a number of other witnesses. 12.  One of those witnesses was a Mr V.K., the personal driver of a Mr P.T., a local businessman. He was arrested by the police on 8 February 1997, and after that kept in custody for a few days in a house in the country near Pleven and repeatedly questioned. According to his subsequent allegations, he was ill‑treated and pressured into testifying in line with the instructions of the police, as well as into identifying certain individuals and objects during identity parades. The police denied these allegations and said that Mr V.K. had made all his statements freely. 13.  Mr V.K. was interviewed by the investigator on 13, 16, 18 and 20 February 1997. He said, inter alia, that on the evening of 3 February 1997 he had seen his boss, Mr P.T., a Mr I.K., and two other men. Mr P.T. had instructed him to go to Stavertsi with Mr I.K. and the two others, in an Audi. When getting out of the car the three men had put masks and gloves on. Mr V.K. had waited for them for a few minutes, during which time he had heard two shots. After that the three had come back to the car, carrying a shotgun. They had driven out of the village and had told Mr V.K. to get out of the car. Mr V.K. had then returned to Mr P.T.’s house, where Mr P.T. had asked him whether the three men had had any United States dollars on them. He had then told him to forget the events of that night. The next day Mr V.K. had heard Mr P.T. and Mr I.K. discussing the incident, with Mr I.K. mentioning a pipe and chair broken in the scuffle, and saying that an old woman had entered and messed up their plans. 14.  Meanwhile, on 15 February 1997 the police seized an Audi, suspected of being the car used by the assailants for their escape. It was inspected on 19 February 1997, and a dark spot measuring four millimetres in diameter was found on the back seat. The same day the investigator asked an expert to determine whether that spot was blood, and if so, of which group. The expert confirmed that the spot was human blood, but could not determine its group because of the insufficiency of the material available for testing. 15.  On 15 February 1997 Mr P.T., Mr I.K. and a Mr V.P. were arrested. On 16 February 1997 Mr P.T. was released, and the investigator carried out an identity parade in which Mr V.K. identified Mr I.K. and Mr V.P. They were then charged and placed in detention. They remained in custody until April 1998, when they were released on bail. 16.  On 21 February 1997 Mr V.K. was presented with a tracksuit seized at Mr I.K.’s home and allegedly worn by him at the time of the offence; he recognised it. 17.  On 25 March 1997 a Mr G.G. was arrested. On 28 March 1997 he was also charged with taking part in the robbery. 18.  On 8 April 1997 the investigator sent the ballistics evidence seized at the crime scene for testing. 19.  Mr V.K. was interviewed again on 12 June 1997. He withdrew his earlier statements and said that he had been coerced by the police into giving false evidence. 20.  On 7 August 1997 the Pleven Regional Prosecutor’s Office, observing that no investigatory steps had been taken for several months, replaced the investigator. 21.  In an interview on 13 August 1997 an individual detained in the same cell as Mr G.G. stated that he had asked him to kill Mr V.K. In an interview of the same date two employees of the country house in which Mr V.K. had been held by the police (see paragraph 12 above) said that while there he had confided in them that he was afraid that his boss, Mr P.T., might kill him because he had testified against him. Mr V.K. had no marks of ill‑treatment. 22.  In August 1997 the Pleven Regional Prosecutor’s Office noted that the accused should remain in custody in view of their apparent resolve to liquidate the witnesses against them. 23.  On 25 September 1997 the investigator ordered Mr P.T.’s detention. Some time after that Mr P.T. was arrested and on 28 October 1997 he was charged. He remained in custody until 18 May 1998. 24.  On 6 and 7 November 1997 the investigator interviewed Mr V.K. again. He again changed his position, reasserting his statements of February 1997 (see paragraph 13 above) and withdrawing his statement of 12 June 1997 (see paragraph 19 above). He said that it had been given under pressure from Mr P.T., who had kidnapped him and deprived him of his liberty for a month. 25.  On 3 and 4 December 1997 Mr V.K. was interviewed again. On 4 December 1997, during an identity parade, he did not recognise Mr G.G. 26.  In a memorandum of 2 September 1998 the head of the Pleven police technical department said that the ballistics evidence seized at the crime scene had been lost when transferred between various departments without the required documents. It was therefore impossible to test it. 27.  No investigative steps were taken in 1998, 1999 and 2000. 28.  On 5 August 1999 the Veliko Tarnovo Appellate Prosecutor’s Office noted that the investigation had suffered from serious setbacks and that not enough had been done to elucidate how and why the missing real evidence had been lost. 29.  On 12 June 2000 Mr Valeri Zashev died. Ms T.L. also died, on 2 October 2000. 30.  On 20 March 2001 the Veliko Tarnovo Appellate Prosecutor’s Office noted that, for no apparent reason, no investigatory steps had been taken after 18 May 1998. It further observed that the file was not bound and ordered properly, which made it difficult to check on the progress of the unfolding of the investigation. It recommended finding out why the case had not been concluded for more than four years and punishing those responsible, as well as taking steps to finalise the case in the near future. Accordingly, on 26 March 2001 the Pleven Regional Prosecutor’s Office instructed the investigator to renew work on the case. 31.  On 23 April 2001 the investigator recommended that the charges be dropped for lack of evidence. The prosecuting authorities disagreed and in July and August 2001 instructed him to question Mr V.K. again and to order a further expert report. However, in the meantime, on 1 August 2001 the investigator left his job and had to be replaced. 32.  On 22 January 2002 the new investigator commissioned a DNA expert report of the blood spot found on the back seat of the seized Audi. On 30 January 2002 the expert said that no blood could be found on the seat. 33.  On 28 May 2002 Mr V.K. was interviewed by the investigator at a public hearing held at the Pleven Regional Court. Mr V.K. stated that he would not testify until measures were taken to protect him, as he had received threats made on behalf of the accused. Accordingly, on 30 May 2002 the investigator requested the police to take measures to protect the witness. The police made contact with Mr V.K. on 18 June 2002. The next day, 19 June 2002, he was asked to go to the police station, where he said that he did not require protection for the time being, but would contact the police if he was threatened again in the future. 34.  On 16 December 2002 Mr V.K. was interviewed again at a public hearing before the Pleven Regional Court. He stated that he had been ill‑treated and pressured by the police into testifying in a certain way about the robbery and into recognising a specific individual during identity parades. He further said that he did not know any of the accused apart from Mr P.T. 35.  On 11 March 2003 the investigator again recommended that the charges be dropped. On 24 March 2003 the Pleven Regional Prosecutor’s Office decided to follow this recommendation. 36.  On an appeal by the applicants, on 16 July 2003 the Pleven Regional Court set this decision aside. It found, inter alia, that it was unclear whether Mr V.K. had made his incriminating statements under police pressure or had retracted them under threats from the accused. The case file contained ample material supporting both versions, but the authorities had done nothing to provide protection for the witness. That had eventually led to him refusing to testify. Nevertheless, the analysis of his statements showed that he had been with the accused both before and after the time when the offence had been committed. The court went on to say that not enough effort had been made to find the lost ballistics evidence. It instructed the investigating authorities to, inter alia, check Mr V.K.’s allegations of police violence against him, take measures to protect him, and then question him again, if need be in the presence of a judge, in order to clarify which of his statements was genuine. The court also said that further efforts should be made to find the missing ballistics evidence. 37.  Between October and December 2003 the investigator interviewed seven police officers who had taken part in the investigation. All of them said that Mr V.K. had given his evidence freely. They were unable to provide definite clues as to the disappearance of the ballistics evidence. 38.  When interviewed on 15 December 2003, Mr V.K. again said that he had been ill-treated by the police and pressured into testifying in a way indicated by them. 39.  On 26 March 2004 the investigator again recommended that the charges against Mr P.T., Mr G.G., Mr V.P. and Mr I.K. be dropped. However, the Pleven Regional Prosecutor’s Office disagreed and on 14 April 2004 indicted them. It alleged that Mr P.T. had incited the rest to rob Mr Ivaylo Zashev and Mr Valeri Zashev; it further alleged that the other three had carried out an armed robbery in the course of which they had killed Mr Ivaylo Zashev. 40.  The trial took place before the Pleven Regional Court (Плевенски окръжен съд) on 15 October and 20 December 2004 and 17 March 2006. The applicants were not summoned and did not take part in it. The court heard numerous witnesses and admitted various documents in evidence. 41.  In a judgment of 17 March 2006 the court acquitted Mr P.T., Mr G.G., Mr V.P. and Mr I.K. of the charges against them. 42.  It found that there was no evidence to show that they had committed the offence. The shotgun had not been found or identified. Likewise, the bullets causing the death of Mr Ivaylo Zashev had not been positively identified. The ballistics evidence found at the crime scene had later been lost because of failure to follow procedures for storing and transporting real evidence, and thus had never been analysed. It was therefore impossible to make any findings about the weapon used to commit the offence or its owner. Furthermore, the investigator had not taken any samples or real evidence from the crime scene, such as tyre or shoe marks, fingerprints or objects, to support even a supposition that any of the accused had been at or even near the crime scene. Nor had the outside of Ms T.L.’s house been checked for traces of the assailants or of the car which they had used to escape. There were no witnesses – save for the brother of the deceased Mr Valeri Zashev and Ms T.L. – who had seen the assailants or the car. The available evidence showed that the Zashevi brothers had neither met the accused or any persons close to them, nor told any of them that they were carrying a sum of money. The analysis of Mr Valeri Zashev’s and Ms T.L.’s statements showed that even they had not seen the assailants properly or identified them. Nor had they seen the car properly. 43.  There was not enough evidence to show that the Audi, which had not been seized until fifteen days after the commission of the offence, had been the one used by the assailants. It had been washed inside and outside before being handed over to the police, and had remained unlocked, including when stored in the police station’s yard. It could not therefore be conclusively established whether the small dark blood spot on its back seat was linked with the offence. The first expert report on this point could not be admitted in evidence, as the investigator’s decision to commission it did not contain any description of the car to be analysed. As to the second expert, he had been unable to reach any conclusion about the blood’s group. 44.  The court went on to say that Mr V.K.’s incriminating statements could not be considered reliable. After analysing in detail the circumstances in which they had been made, it found that it was clear that Mr V.K. had been pressured by the police, who had detained him unlawfully, to testify in a way indicated by them. Nor did the court find the identity parades carried out with Mr V.K.’s participation reliable. Contrary to the rules of procedure, he had not been asked about any distinctive features of the individuals to be recognised before the identification, nor had those individuals been lined up among persons who resembled them. Moreover, Mr V.K. had been instructed whom to identify and on the basis of what physical features. 45.  Finally, the expert examination of the clothes seized at Mr I.K.’s home showed that there were no traces of blood on them. 46.  No other evidence had been put forward by the prosecution to link any of the accused to the commission of the offence. 47.  The prosecution appealed, arguing that the acquittal was ill-founded. 48.  On 30 May 2006 the Veliko Tarnovo Court of Appeal (Великотърновски апелативен съд) set the case down for hearing. It noted that the appeal did not point to specific irregularities in the lower court’s judgment, and that there was no request for further evidence to be gathered. 49.  At the hearing, which took place on 18 September 2006, the prosecutor on appeal reluctantly endorsed the appeal. He did not call further evidence. 50.  In a judgment of 4 October 2006 the Veliko Tarnovo Court of Appeal upheld the acquittal. It found that the lower court had properly analysed the entirety of the available material, finding that key pieces of evidence had been lost or spoiled. Its conclusion that the evidence adduced could not link the accused to the commission of the offence had been fully warranted. No arguments had been put forward by the prosecution in the appeal proceedings to cast doubt on that finding. 51.  The prosecution did not appeal again and the judgment became final on 24 October 2006.