The right of defence in criminal proceedings: what it includes and where its limits lie
Criminal proceedings place the individual against the power of the State in its most coercive manifestation: investigation, accusation, pre-trial detention, the threat of a penalty. The right of defence is the main counterweight to that power, the guarantee that allows the accused to resist and rebut the accusation with the same tools that the system gives to the accuser. It is not a privilege, but a structural guarantee of the rule of law: without it, the process would cease to be fair and would become a foregone conviction.
Its basis is in Article 24 of the Constitution, which recognises effective judicial protection and the right to a process with all the guarantees, and in Article 6 of the European Convention on Human Rights. It is not a single right, but a bundle of specific powers that unfold throughout the entire process.
The first is the right to be informed of the accusation: to defend oneself, one must know what one is accused of, with sufficient precision at each stage. The second is the right of access to the case file, to prepare the defence with all the available information; its only limit during the investigation is the secrecy of the proceedings, which is temporary and reasoned. The third is the right to propose favourable investigative measures, which the judge can only refuse by way of a reasoned decision. The fourth is the right to legal assistance, practically inseparable from the right of defence owing to the technical complexity of the process; it must be real and effective assistance, not merely formal.
To this are added the accused's right to the last word, the right to challenge the prosecution's evidence by questioning its witnesses and challenging its experts, and the right to propose and present one's own evidence. The right of defence is exercised differently at each stage: at the time of arrest, through immediate legal assistance and the right to silence; during the investigation, by proposing measures and challenging precautionary measures; in the intermediate phase, with the defence brief; at the oral trial, with cross-examinations, the oral report and the last word; and in appeals, by challenging the judgment.
Like every right, it has limits. The main one is procedural good faith: the defence may allege anything useful, but may not lie to the court, present false evidence or use procedural mechanisms abusively to delay the process. Another limit is the protection of victims and witnesses: the right to question does not cover degrading conduct, especially in sexual or violence offences. And the lawyer's professional secrecy does not cover collaboration in an offence.
The infringement of the right of defence has serious consequences: the nullity of the proceedings when it has generated a real and effective lack of defence, which can be invoked as a ground of appeal and, ultimately, of an appeal for protection (amparo) before the Constitutional Court. That is why the early detection of infringements is an essential task of the lawyer: an infringement not raised in time may be deemed consented to.
The right of defence is the same for all accused persons, whatever the offence charged or the social revulsion it generates. It is not a privilege granted to the offender: it is a guarantee that protects all citizens, because a system that reduced the guarantees for certain offences could tomorrow be used against anyone.
