34 ANGUELOVA v. BULGARIA JUDGMENT applicant's joining the criminal proceedings as a civil party) was consequently undermined, the Court finds that the State has failed in its obligation under Article 13 of the Convention. There has therefore been a violation of that Article. V. ALLEGED VIOLATION OF ARTICLE 14 OF THE CONVENTION 163. The applicant complained under Article 14 of the Convention taken in conjunction with Articles 2, 3 and 13 that the police officers' and the investigating authorities' perception of her son as a Rom/Gypsy was a decisive factor in their attitude and acts. Article 14 of the Convention provides: “The enjoyment of the rights and freedoms set forth in [the] Convention shall be secured without discrimination on any ground such as sex, race, colour, language, religion, political or other opinion, national or social origin, association with a national minority, property, birth or other status.” 164. The applicant considered it striking that some of the police officers had been unable to refrain from referring to Mr Zabchekov as “the Gypsy”, even in their official statements. She considered that the reference to her son's origin and the acts of the police and the investigation authorities had to be seen against the broader context of systematic racism and hostility which law-enforcement bodies in Bulgaria had repeatedly displayed. This attitude had been widely documented by intergovernmental and human rights organisations. 165. The Government submitted that there was no evidence of any racially motivated act on the part of the authorities. The fact that some statements referred to Mr Zabchekov as “the Gypsy” did not constitute such evidence. 166. The Court reiterates that proof “beyond reasonable doubt” may follow from the coexistence of sufficiently strong, clear and concordant inferences or of similar unrebutted presumptions of fact (see paragraph 111 above and the case-law cited there). The Court must therefore assess all the relevant facts, including any inferences that may be drawn from the general information adduced by the applicant about the alleged existence of discriminatory attitudes. 167. It recalls that in Velikova it examined a very similar complaint in paragraph 94 of that judgment and held: “The Court observes that the applicant's complaint under Article 14 is grounded on a number of serious arguments. It also notes that the respondent State failed to provide a plausible explanation as to the circumstances of Mr Tsonchev's death and as to the reasons why the investigation omitted certain fundamental and indispensable steps which could have shed light on the events ... The Court recalls, however, that the standard of proof required under the Convention is 'proof beyond reasonable doubt'. The material before it does not enable