A selection of key paragraphs can be found below the judgment.
87. The Court recalls that it found the application of Peruzzo and Martens, cited above, to be inadmissible on the basis that it was manifestly ill-founded. In that case, the applicants had been repeatedly convicted of serious offences and sentenced to prison. The law provided for the indefinite retention of their biometric data. That data was retained for those convicted of serious and/or repeat offences, and the Federal Criminal Office was obliged to review at regular intervals whether the continued storage of the data was still necessary for the performance of its task or otherwise to be deleted at the latest every ten years. However, the Court has also found a regime with a definite retention period of forty years in law but which amounted to an indefinite period in practice, to be in violation of the Convention (see Aycaguer v. France, no. 8806/12, § 42, 22 June 2017). In that case, the applicant was convicted of a minor offence and subject to fine. His biometric data was retained under provisions which did not differentiate according to the nature and/or seriousness of the offence committed, and he had no possibility to request the deletion of the data (see Aycaguer, cited above, §§ 43-47). It also notes that the Court was satisfied in Peruzzo and Martens, cited above, that there was nothing to establish that the domestic courts or authorities in the proceedings at issue had not observed the relevant guarantees (see § 48). Whereas in Aycaguer, cited above, the authorities’ failure to implement a decree had created a degree of ambiguity in the legal provisions governing the retention of data, and they had not given any follow up to the decision of the Constitutional Council of 16 September 2010 criticising the regime then in force (see §§ 42-43).
88. There is a narrowed margin of appreciation available to States when setting retention limits for the biometric data of convicted persons (see paragraph 84 above). However, in light of the considerations set out above (see paragraph 87) the Court considers that in respect of retention regimes for the biometric data of convicted persons, the duration of the retention period is not necessarily conclusive in assessing whether a State has overstepped the acceptable margin of appreciation in establishing the relevant regime. In that connection, it underlines that there is not the same risk of stigmatisation in retaining the data as in S. and Marper (cited above, § 122). Also of importance is whether the regime takes into account the seriousness of the offending and the need to retain the data, and the safeguards available to the individual. Where a State has put itself at the limit of the margin of appreciation in allocating to itself the most extensive power of indefinite retention, the existence and functioning of certain safeguards becomes decisive (see Catt, cited above, § 119).
94. Having chosen to put in place a regime of indefinite retention, there was a need for the State to ensure that certain safeguards were present and effective for the applicant (see paragraph 88 above), someone convicted of an offence (now spent, see paragraph 7 above). However, the applicant’s biometric data and photographs were retained without reference to the seriousness of his offence and without regard to any continuing need to retain that data indefinitely. Moreover, the police are vested with the power to delete biometric data and photographs only in exceptional circumstances (see paragraph 30 above). There is no provision allowing the applicant to apply to have the data concerning him deleted if conserving the data no longer appeared necessary in view of the nature of the offence, the age of the person concerned, the length of time that has elapsed and the person’s current personality (see Gardel v. France, no. 16428/05, § 68, ECHR 2009). Accordingly, the review available to the individual would appear to be so narrow as to be almost hypothetical (see paragraph 31 above, and also M.K. v. France, no. 19522/09, § 25, 18 April 2013).
96. For the reasons set out above, the Court finds that the indiscriminate nature of the powers of retention of the DNA profile, fingerprints and photograph of the applicant as person convicted of an offence, even if spent, without reference to the seriousness of the offence or the need for indefinite retention and in the absence of any real possibility of review, failed to strike a fair balance between the competing public and private interests. The Court recalls its finding that the State retained a slightly wider margin of appreciation in respect of the retention of fingerprints and photographs (see paragraphs 84 above). However, that widened margin is not sufficient for it to conclude that the retention of such data could be proportionate in the circumstances, which include the lack of any relevant safeguards including the absence of any real review.