This thesis examines the principle of effective participation under article 6 of the European Convention on Human Rights (ECHR) and article 13 of the Convention on the Rights of Persons with Disabilities (CRPD). It focuses on decisions on preliminary investigation limitation and abstention from prosecution in cases where the accused suspect has intellectual disability and receives care.

The study is based on a legal dogmatic method, utilizing primary legal sources such as legislation, case law, preparatory works and doctrine, as well as reports from public Swedish authorities to deepen the analysis. The study uses a subjective teleological method to determine the purpose of the provisions, in relation to the overall context of the legal framework and how they can be interpreted in relation to each other.

The findings show a connection between the principle of effective participation and decisions regarding preliminary investigation limitation and abstention from prosecution in cases where the accused suspect has intellectual disability and receive care. Effective participation entails the accused suspect’s right to understand and participate in the legal process. Authorities are obligated to identify vulnerable accused suspects and provide procedural accommodations if necessary. This is consistent with both the ECHR and CRPD, as well as the European Commission’s recommendations on procedural safeguards for vulnerable suspects or defendants.

For accused suspects with intellectual disabilities who recive care, decisions concerning preliminary investigation limitation and abstention from prosecution may be relevant. Therefore, it is crucial for the legal framework to clarify which procedural rights should be particularly considered in these cases. When accused suspects have intellectual disability, it may signal the need for procedural accommodations to facilitate effective participation. If the defendant is unable to understand or participate in the legal process it may support a decision on preliminary investigation limitation and abstention from prosecution, aligning with the aims of the legislation prioritizing care over prosecution when a trial would be deemed ineffective under the circumstances. A central issue in these decisions concerns the accused suspect’s ability to understand and participate in the legal process, which is often closely related to the accused’s disability and need of care. To ensure well-grounded decisions, it is crucial that investigating authorities assess the accused suspect’s capacity to participate effectively. However, Sweden currently lacks a national strategy or guidelines on this matter, creating a risk that procedural safeguards may not be fully implemented in practice.