Spanish Supreme Court (plenary): EncroChat data admissible, but probative value must be assessed case by case

In plenary judgment STS 854/2025 of 16 October 2025 the Criminal Chamber of the Spanish Supreme Court dismissed five appeals against drug-trafficking convictions and held EncroChat data obtained from France by European Investigation Order admissible. Several holdings assist the defence. The omission of the Art. 31 notification is a procedural irregularity that leads to nullity where it caused actual prejudice to the defence or was meant to circumvent the issuing State's safeguards. Under Art. 14(7) of the Directive the accused must be able to challenge the data themselves, including their integrity and chain of custody. The court acknowledged a cascade selection in which the defence never received the raw data and, applying Yüksel Yalçınkaya, required particular caution where data were processed by several authorities or carry preponderant weight. Probative value depends on each case; here the chats were merely corroborative.