CRIMINAL LAW DIVISION
One of the issues of greatest constitutional sensitivity in criminal proceedings arises when a person appears and gives evidence formally as a witness even though objective evidence already exists that could attribute possible criminal responsibility to that individual in relation to the facts under investigation.
It is in this context that legal scholarship and case law have developed the concept of the so-called “proto-suspect” (protoimputado).
This issue is far from being merely terminological or conceptual. On the contrary, it has significant practical consequences from the perspective of procedural safeguards. A witness is subject to the legal duty to tell the truth, whereas a person under investigation enjoys a reinforced set of defence rights, including the right to remain silent, the right not to incriminate oneself, the privilege against self-incrimination, and the right to legal assistance from the very moment criminal responsibility is attributed.
For this reason, European, constitutional, and ordinary courts have repeatedly stressed that the right of defence cannot depend upon the formal decision of when a person is officially designated as a suspect.
Particularly relevant in this regard is Supreme Court Judgment (Criminal Chamber) No. 836/2021 of 3 November [ES:TS:2021:4054], which contains an important reflection on the need to activate defence rights immediately from the moment a person becomes objectively linked to a criminal offence. Specifically, the Supreme Court stated:
“There can be no doubt—or there should be none—that from the moment a criminal act is attributed to a person, that individual has the right, with the greatest possible promptness, to defend themselves and to be informed of the reasons for such attribution of criminal responsibility.”
This statement is particularly significant because it shifts the focus from formal accusation to the substantive reality of the investigation. In other words, what matters is not merely when the investigating judge formally grants a person the status of suspect, but rather when objective elements already exist that allow that person to be regarded as a potential criminally liable party. It is precisely at that point that the issue of the proto-suspect arises.
The judgment recalls that both Directive 2012/13/EU on the right to information in criminal proceedings and Articles 118 and 520 of the Spanish Criminal Procedure Act require that a person be informed of the accusation against them at an early and effective stage, ensuring the immediate activation of the rights inherent in the right of defence. This is not simply a formal or procedural requirement; rather, it is a structural guarantee directly linked to the fairness of criminal proceedings and the effective protection of defence rights.
The prompt communication of an accusation constitutes an essential safeguard of both the right of defence and the fairness of criminal proceedings. Accordingly, the Supreme Court emphasises that unjustified delays in granting a person the status of suspect may not only create a situation of material defencelessness but may also undermine the validity of certain investigative measures:
“The Constitutional Court, in its important Judgment STC 135/1989, emphasised that the bundle of defence guarantees derived from the Constitution requires Article 118 of the Criminal Procedure Act to be interpreted as prohibiting, on the one hand, the unjustified delay in conferring the status of suspect upon a person who may appear responsible for the criminal act under investigation and, on the other hand, taking advantage of such delay to question the proto-suspect in the capacity of a witness.”
The principle underlying this doctrine is unequivocal: it is constitutionally unacceptable to use witness testimony as a means of obtaining potentially incriminating information from someone who, in light of the objective circumstances of the investigation, should already be protected by the safeguards attached to the status of a person under investigation.
This is because criminal proceedings cannot rest upon purely formal constructions that, in practice, result in the restriction or erosion of the right of defence and the fundamental guarantees that comprise it.
Indeed, the judgment itself warns that such improper delay may have significant procedural consequences, including the possible loss of evidential value of certain statements made during the investigation phase where the defence has been improperly deprived of the opportunity to participate and challenge the evidence through adversarial proceedings.
Ultimately, the concept of the proto-suspect highlights a fundamental principle of procedural safeguards: the rights associated with the status of a person under investigation under Article 118 of the Criminal Procedure Act are not dependent upon a formal declaration of suspicion. Rather, those rights must arise from the very moment a person materially occupies a position of suspicion or potential criminal liability within the proceedings.
For precisely that reason, artificially delaying the granting of that procedural status is not merely a technical irregularity. It is an issue directly linked to the fundamental right of defence and to the overall fairness of the criminal process itself.
