When a sexual-assault sentence must be reviewed under the 2022 reform in Spain

Organic Law 10/2022 on the comprehensive guarantee of sexual freedom substantially amended the offences under Arts. 178 and 179 of the Criminal Code (CP). Among its most significant effects is the reduction of the minimum sentence threshold for certain conduct. That change raises a technically important question: where the new law is more favourable to the convicted person, does it require the sentence already imposed to be revised? STS 20/2026, of 20 January, answered that question with a clear test that guides pending sentence reviews.

Background and issues raised

The appellant had been convicted of sexual assault under Arts. 178 and 179 CP in the version prior to LO 10/2022, and sentenced to six years' imprisonment — the legal minimum then in force — with ancillary penalties under Art. 192 CP. Three distinct issues were raised in cassation: the impartiality of the court, the use of leading questions during examination at trial, and the retroactive application of LO 10/2022 as the more favourable criminal law.

The Second Chamber of the Supreme Court dismissed the first two grounds but partly allowed the third, resulting in a reduction of the custodial sentence.

Leading questions: irregularity, not automatic nullity

One ground of appeal challenged the use of leading questions at trial. The Chamber set out the following principle: allowing leading questions is, in principle, a mere procedural irregularity. It does not in itself generate nullity or automatically invalidate the evidence taken.

For the irregularity to found a cassation ground it must have caused an actual breach of a procedural fundamental right — notably the right of defence, the right to use relevant evidence, or the right to a fair trial under Art. 24.2 of the Spanish Constitution. On the facts, the Chamber found that no such real impact on the defendant's rights had occurred and dismissed the ground.

This doctrine is consistent with the Supreme Court's settled approach distinguishing formal irregularity from substantive defencelessness: not every procedural breach carries invalidating consequences unless it results in real and effective prejudice to the party raising it.

The more-favourable-criminal-law doctrine

The core of the ruling lies in the application of the Plenary doctrine of the Second Chamber on the retroactivity of the more favourable criminal law. Art. 2.2 CP provides that criminal laws that benefit the offender shall have retroactive effect. LO 10/2022 amended the sentencing ranges of Arts. 178 and 179 CP; in certain cases the new minimum is lower than the one previously in force.

The test set is the following: where the trial court imposed precisely the legal minimum then in force, comparison with the new sentencing framework is mandatory. If LO 10/2022 sets a lower minimum for the same conduct, the sentence must be adjusted to that new minimum, because the later law is more favourable and the principle of retroactivity in bonam partem so requires.

The Chamber stresses that this mechanism does not operate automatically in every case: the comparison must be made in concreto, taking into account the sentence actually imposed and the margin available to the court. Where a higher sentence than the former minimum could have been imposed and the minimum was chosen, the new more favourable law applies directly to that result.

Application to Arts. 178, 179 and 192 CP

In the case resolved, the conviction rested on Arts. 178 and 179 CP — basic sexual assault and its aggravated form — and Art. 192 CP for ancillary penalties. The six-year sentence was the minimum prescribed by the former version of Art. 179 CP for the offence as then charged.

Under LO 10/2022, the new framework of Art. 179 CP provides a lower minimum for that conduct. The Chamber substituted the sentence by applying the new, more favourable minimum, reducing the sentence from six to four years' imprisonment. The ancillary penalties under Art. 192 CP were recalculated accordingly.

This adjustment does not involve any re-examination of the proven facts or the legal characterisation: the conduct remains constitutive of the same offence. What changes is solely the length of the sentence, which must be aligned with the more favourable framework introduced by the reform.

Relevance for pending sentence reviews

STS 20/2026 has direct reference value for sentence reviews under the transitional provision of LO 10/2022. The test it supplies is precise: identify whether the trial court imposed the then-applicable legal minimum and compare it with the new minimum of LO 10/2022 for the same conduct.

If the comparison yields a result favourable to the convicted person, the review is warranted even where the sentence is final: the retroactivity of the more favourable criminal law applies to final sentences, including those being served, under the terms set by the CP and the transitional provision of LO 10/2022 itself. Each case requires an individual analysis of the articles applied, the specific sentence imposed, and the sentencing margin under the new provisions.

Technical conclusion

STS 20/2026 clarifies two points of procedural and criminal-law technique with practical utility. First, it delimits the cassation scope of leading questions, requiring that the irregularity produce actual defencelessness. Second, it applies the retroactivity in bonam partem principle of LO 10/2022 with precision: where the former minimum was imposed and the new minimum is lower, review is warranted. These are technical criteria to be assessed case by case in light of the specific sentence imposed and the framework of Arts. 178, 179 and 192 CP in their successive versions.