Cross-Border Digital Evidence in Spanish Criminal Law
When a criminal investigation crosses borders, the evidence it generates does too. But does evidence lawfully obtained abroad become automatically admissible before Spanish courts? The Plus Ultra case is forcing that question to the surface, and the answer is more complex than it might appear.
Is Foreign Evidence Automatically Admissible in Spain?
Spanish criminal procedure does not operate on the assumption that foreign legality is enough. Evidence obtained abroad must still satisfy the procedural requirements of Spanish law to be admitted at trial. The fact that another jurisdiction followed its own rules does not mean those rules align with Spain's constitutional standards.
This distinction matters. The right to a fair trial, enshrined in Article 24 of the Spanish Constitution, places affirmative obligations on Spanish courts, regardless of where the evidence originated.
The EncroChat Doctrine Does Not Settle the Question
The EncroChat case established that evidence obtained through foreign interception operations can, in principle, be used in Spanish proceedings. But it did not eliminate the obligation to verify that specific evidence.
Two issues remain open even after EncroChat: the authenticity of the material and its integrity during transfer. Digital evidence is particularly vulnerable to alteration. Without verification, its probative value is uncertain, and its admission potentially unconstitutional.
Chain of Custody as a Constitutional Safeguard
The chain of custody is not a procedural formality. It is the mechanism that links a piece of evidence to the event it purports to prove, and it is the only basis on which a court can be confident the material has not been tampered with.
When evidence is collected in a foreign jurisdiction and transferred to Spain, the chain of custody must be documented and verifiable at every step. Gaps in that record are not minor defects. They can render evidence inadmissible , and rightly so.
The Principle of Speciality Limits How Evidence Can Be Reused
Evidence gathered under an international cooperation request for one investigation cannot automatically be repurposed for another. The principle of speciality, which governs mutual legal assistance between states, requires that the material only be used for the purpose for which it was obtained.
In practice, this means prosecutors must carefully assess whether evidence collected in a different context can lawfully support new charges. Courts must apply the same scrutiny.
Conclusion
The Plus Ultra proceedings highlight a gap that is becoming harder to ignore: Spanish courts need clear, consistent standards for evaluating cross-border digital evidence. International cooperation should not come at the cost of procedural guarantees.
At Fukuro Legal, we advise clients facing cross-border criminal investigations in Spain. If you have questions about how evidence obtained abroad may affect your case, contact our team.
Read the full analysis by Managing Partner Jorge Agüero Lafora in Noticias Jurídicas →
