The undeniable impact of the European Convention on Human Rights on the legal systems – and the wider society – of Member States of the Council of Europe would not have been possible without its unique monitoring system, centred around the European Court of Human Rights and the Committee of Ministers of the Council of Europe. The present article assesses the extent to which the European Court's judgments that have found violations of the procedural obligations under Articles 2 and 3 of the Convention to investigate unlawful killings, disappearances, acts of torture or other ill-treatment have, in fact, led to an improvement in the capability of the domestic legal systems of states parties to ensure accountability for such abuses. On the basis of four case studies, it is concluded that the European Court's judgments, coupled with the supervisory powers of the Committee of Ministers, have the potential to make a very great impact on the capability of domestic legal systems to deal with gross violations of fundamental human rights, and have led to clear and positive changes within the domestic legal systems of respondent states. Nevertheless, this is by no means always the case, and it is suggested that, in order for the Convention system to achieve its full potential in the most politically charged cases, the European Court should adopt a more proactive approach to its remedial powers by ordering specific remedial measures, to include in particular the opening or reopening of investigations.