Article 324 LECrim and the time limits for investigation: judicial protection and the pro actione principle

The reform of Article 324 of the Criminal Procedure Act (LECrim) introduced strict time limits for the criminal investigation phase with the aim of guaranteeing procedural speed and avoiding undue delays. However, its literal application is generating controversial situations that compromise effective judicial protection and the very purpose of criminal investigation.

This paper argues that the interpretation of Article 324 should be teleological and systematic, harmonised with constitutional principles and with the function of criminal law to protect legal assets and preserve social order.

Introduction

The reform of Article 324 LECrim incorporated strict time limits for the criminal investigation phase, with the aim of guaranteeing procedural speed and avoiding undue delays. However, the literal and rigid application of the precept has given rise to controversies which, on occasions, disconnect the temporal mandate from its purpose and generate scenarios of defencelessness, especially when the expiry of the time limit is due to internal incidents of the judicial body or work overload beyond the control of the parties.

This article examines the problems derived from the restrictive interpretation of Art. 324, which leads to the premature termination of the investigation and the provisional dismissal of proceedings despite the existence of facts with the appearance of criminality and the prior request for extension made in time by the parties.

Regulatory framework and guiding principles

The regime of Article 324 LECrim

Article 324 LECrim stipulates that the investigation must be concluded within a maximum period of twelve months from the initiation of the case, which may be extended by means of a reasoned decision issued before its expiry. The purpose is twofold: to ensure the effectiveness of the investigation and to avoid undue delay.

The function of criminal law and the need for prosecution

The Preamble to the Criminal Code stresses that the function of criminal law is the protection of essential legal interests and the effectiveness of the system of punishment, an expression of the principle of legality. This purpose implies that typical conducts should not go unpunished, reinforcing the obligation to prosecute crimes provided for in our legal system:

• Spanish Constitution, art. 124.1: mission of the Public Prosecutor's Office to promote the action of justice ex officio or at the request of the interested parties.
• LECrim, art. 105: duty of the Public Prosecutor's Office to bring the criminal actions it deems appropriate.
• Criminal Code, arts. 407 and 408: criminalisation of abandonment of post and omission of the duty to prosecute crimes by authority or civil servant, respectively.

Effective judicial protection and hierarchy of norms

Article 24 EC enshrines the fundamental right to effective judicial protection, which includes access to jurisdiction and obtaining a decision based on law, proscribing formalistic obstacles lacking sufficient justification.

Article 5.1 LOPJ imposes on judges and courts the duty to interpret and apply the rules in accordance with the Constitution and fundamental rights, taking into account the doctrine of the Constitutional Court.

Added to this is the principle of hierarchy of norms, which guarantees the coherence and supremacy of the legal system by preventing a lower-ranking norm from contradicting a higher-ranking norm. This principle, enshrined in Article 9.3 of the Spanish Constitution - which states that 'the rules regulating the different legal orders (...) may not contradict the provisions of this Constitution' - and in Article 1.2 of the Civil Code - which states that 'provisions which contradict another of higher rank shall be invalid' - requires that the Criminal Procedure Act, as an ordinary law, be interpreted in a manner compatible with the Constitution and with organic laws, including the Criminal Code, never in opposition to their mandates.

Practical problems: unagreed extensions and automatic dismissals

Practical experience shows cases in which the examining court does not grant the extension in due time and form in accordance with art. 324 LECrim, despite the fact that the party requested it sufficiently in advance. This sometimes happens due to processing errors, organisational incidents or structural overload. As a consequence, the expiry of the time limit precipitates provisional dismissal agreements, with the real effect of halting investigations into facts that present indications of a crime.

In our opinion, this automatic reading of the expiry of the time limit and the closure of the investigation is an excessively rigid interpretation, disconnected from the purpose pursued by the precept and contrary to the pro actione principle, especially when there is no material defencelessness for the person under investigation and the delay is due to internal dysfunctions beyond the control of the parties.

Doctrinal and jurisprudential reasoning

The Constitutional Court has reiterated that the pro actione principle operates with maximum intensity in access to jurisdiction, prohibiting formalistic interpretations that unjustifiably hinder the fundamental right (see, among others, STC 10/2022).

For its part, the Supreme Court has warned that procedural formalisms cannot become barriers to the prosecution of crimes when there is no material defencelessness for the person under investigation. In particular, it has pointed out that the time limits set out in Article 324 of the Criminal Procedure Act are instruments to avoid undue delays, not to provoke situations of impunity. It is, therefore, a procedural guarantee, not a limit of constitutional rank, so that non-compliance does not automatically entail a violation of the right to defence (see, for example, STS 317/2025 and 502/2025; and recent doctrine on the subject of investigation deadlines and proceedings carried out after the deadline). Likewise, STS 871/2023 underlines that the procedural impulse corresponds to the judicial body and the Public Prosecutor's Office, who must adopt measures to avoid prejudice derived from internal errors.

In criminal doctrine, authors such as Muñoz Conde argue that rigour in the application of the rules is not equivalent to a literal interpretation devoid of material meaning: the purpose of the precept should guide the reading, ensuring an effective investigation and preventing the injured party from bearing the consequences of other people's errors.

Interpretative proposal: a teleological and systematic reading of Article 324.

Purpose as a hermeneutic criterion

The interpretation of Art. 324 LECrim must be teleological, taking into account its ultimate aim: to ensure the effectiveness of the investigation and avoid undue delays. This does not justify converting the precept into an automatic closing mechanism when the expiry of the time limit derives from incidents not attributable to the parties and does not entail defencelessness.

Test of actual lack of defence

It is proposed that a test of real defencelessness be applied: as a decision-making criterion prior to the adoption of a measure as burdensome as the dismissal due to the expiry of the investigation period, the judicial body must make a concrete assessment of the development of the proceedings and verify whether the delay has caused substantial harm to the person under investigation (e.g., limitation of the defence, loss of exculpatory evidence, infringement of fundamental rights). In the absence of such prejudice, the purpose of the investigation must take precedence.

The weight of the judicial body and the public prosecutor's office in the prosecution process

The judicial body and the Public Prosecutor's Office are primarily responsible for the procedural momentum. Failure to extend the deadline due to internal errors or workload should not have negative effects on the public interest or on the victim. Shifting the consequences of dysfunctions inherent to the functioning of the system onto these subjects would be a breach of the balance between guarantees and efficiency that should govern criminal investigation. In the face of such situations, corrective measures should be adopted to avoid prejudice arising from such dysfunctions, otherwise the time limit would cease to operate as a guarantee and would become a procedural sanction with no constitutional basis.

Compatibility with the Constitution and the hierarchy of norms

The LECrim, as an ordinary law, must be interpreted and applied in accordance with the Constitution (arts. 24 and 9.3 CE) and the guiding principles of the LOPJ (art. 5.1).

The right to effective judicial protection (art. 24 CE) is not limited to the guarantees of the person under investigation, but also includes the right of victims and society to obtain a well-founded judicial response on the merits of the case, provided that the process is carried out with respect for the essential guarantees. For its part, the principle of hierarchy of norms (Art. 9.3 CE and Art. 1.2 CC) prevents readings that distort effective judicial protection or frustrate the guaranteeing function of Criminal Law.

From this perspective, art. 324 LECrim must be subject to a constitutionally oriented reading, which avoids a rule of ordinary legal rank having effects that are materially incompatible with fundamental rights and basic principles of the legal system.

Consequently, the time requirement set out in Article 324 cannot lead to impunity for administrative incidents, when there is a public interest in the prosecution and there is no real defencelessness, as this would lead to materially unjust results or be contrary to the constitutional function of criminal proceedings.

Conclusion

• Article 324 LECrim seeks investigative efficiency and speed, not the automatic closure of the investigation due to incidents beyond the control of the parties.
• The teleological and systematic reading of the precept, in the light of Art. 24 CE, Art. 5.1 LOPJ, the hierarchy of norms (Art. 9.3 CE and Art. 1.2 CC) and the function of Criminal Law (Preamble CP), requires avoiding formalistic interpretations that compromise effective judicial protection.
• A real defencelessness test should be applied before dismissing cases due to expiry of the time limit, weighing up the public interest and the protection of legal assets.
• The internal management of time limits should be strengthened, extensions should be properly justified and investigative activity should be planned, preventing administrative errors from translating into impunity.
• Coordination between the judiciary and the Public Prosecutor's Office is essential so that the temporary regime of Art. 324 contributes to efficiency without harming fundamental rights.

Tribune written by Silvia Zamorano, partner, and Marta Coro, junior associate in the Compliance area of ECIJA Madrid and published in Elderecho.com.