Hearsay and the ECHR
The Al Khawaja saga resumed when the Grand Chamber, after reviewing the Supreme Court’s reasoning in Horncastle retreated partially from their earlier view, concluding that (1) the admissibility of evidence is a matter for regulation by national law and the national courts and that the Court’s only concern is to examine whether the proceedings have been conducted fairly. (2) Article 6 § 3(d) enshrines the principle that, before an accused can be convicted, all evidence against him must normally be produced in his presence at a public hearing with a view to adversarial argument. Exceptions to this principle are possible but must not infringe the rights of the defence, which, as a rule, require that the accused should be given an adequate and proper opportunity to challenge and question a witness against him, either when that witness makes his statement or at a later stage of proceedings. (3) There are two requirements which follow from the above general principle. First, there must be a good reason for the non-attendance of a witness. Second, when a conviction is based solely or to a decisive degree on depositions that have been made by a person whom the accused has had no opportunity to examine or to have examined, whether during the investigation or at the trial, the rights of the defence may be restricted to an extent that is incompatible with the guarantees provided by Article 6 (the so-called “sole or decisive rule”). (4) where a hearsay statement is the sole or decisive evidence against a defendant, its admission as evidence will not automatically result in a breach of Article 6 § 1. At the same time where a conviction is based solely or decisively on the evidence of absent witnesses, the Court must subject the proceedings to the most searching scrutiny. Because of the dangers of the admission of such evidence, it would constitute a very important factor to balance in the scales, and one which would require sufficient counterbalancing factors, including the existence of strong procedural safeguards. The question in each case is whether there are sufficient counterbalancing factors in place, including measures that permit a fair and proper assessment of the reliability of that evidence to take place. This would permit a conviction to be based on such evidence only if it is sufficiently reliable given its importance in the case.
(Al Khawaja and Tahery v The United Kingdom  ECHR 2127, 54 EHRR 23,  ECHR 2127, 32 BHRC 1,  Crim LR 375, (2012) 54 EHRR 23.
6th Edition » | Chapter 12