Could the evidence obtained by using a hidden camera be considered null in a criminal case in Spain?
The Sentence of the Spanish Supreme Court STS 72/2017 of February 8th, collects the six conclusions in this regard in light of the extensive jurisprudential doctrine of the Spanish Constitutional Court and the European Court of Human Rights:
The use in criminal proceedings of recordings of private conversations recorded by one of the interlocutors does not in any case violate the constitutional right to confidentiality of communications (art. 18.3 of the Spanish Constitution).
Nor does it violate the constitutional right to privacy (art. 18.1 Spanish Constitution), but in exceptional cases in which the content of the conversation affects the intimate nucleus of the personal or family privacy of one of the interlocutors.
They violate the fundamental right not to testify against oneself and not to confess guilty, and consequently incur a probative nullity, when the recordings have been made from a position of institutional superiority (agents of the authority or hierarchical superiors) to obtain a confession extra-procedural extracted by deception, except in the cases of recordings authorized by the judicial authority in accordance with articles 588 and following of the Spanish Criminal Procedure Law.
They do not violate the fundamental right not to testify against oneself and not to confess guilt, when they have been carried out in the private sphere.
They can violate the right to a trial with all the guarantees, if the recorded person has been led to the meeting using tricks with the intention of making him manifest facts that could be used against her/him, in which case the concurrent circumstances will have to be weighed.
The jurisprudential doctrine does not qualify the statements made by the accused in these recordings as a confession, using the recordings as ratification of the statements of the other participants in the conversation, which have the value of reference testimony on the statements of the accused.