¿Inconstitucionalidad o inaplicabilidad? El Acuerdo Plenario 05-2023/CIJ-112 y un dilema de dos naturalezas en el mismo sistema jurídico

On November 28, 2023, the Supreme Court of Peru issued Plenary Decision 05-2023/CIJ-112, which established that Law 31751 was unconstitutional and, consequently, recommended its non-application to other judges nationwide. This jurisprudential document blurred the boundaries between the judicial review and concentrated control of constitutionality both instituted in the Peruvian system, causing this decision, in practice, to occupy the jurisdiction of the Constitutional Court. Consequently, a normative dilemma has arisen for criminal judges, affecting legal certainty and the coherence of the legal system, which, as a matter of principle, requires certainty and stability as essential conditions for protecting the rights of those seeking justice and for the normal functioning of the judicial system. The Supreme Court has reaffirmed its position in subsequent jurisprudence; however, many judicial bodies have departed from the Plenary Decision, arguing that it violates its nomophylactic, hermeneutical, restricted to specific cases and regulating the system nature, but not legislative, and even less so, repealing, negatively affecting the principle of legal certainty. This situation requires relocating the original limits of judicial review—that is, concrete rather than general—because if the opposite were ac cepted, we would be conceding that a judicial body can repeal a law, a function that falls solely to the concentrated control of the Constitutional Court, according to the Peruvian Constitution.