The most up-to-date and relevant documents, press releases, academic comment, legislation, and case-law is collated and organised here in this fully-searchable central storage space. Here you can get an overall sense of the information available in the area of procedural rights or quickly find a specific document.
The Directive on the right to interpretation and translation in criminal proceedings was adopted by the European Parliament and the Council of European Union with a view to implementing the principle of mutual recognition of decisions in criminal matters. The Directive lays down rules concerning the right to interpretation and translation in criminal proceedings and proceedings for the execution of a European arrest warrant. Official summaries of the legislation can be found here and here.
National implementing measures - laws and regulations passed at Member State level to implement the Directive - can be found on the Eur-Lex website. According to the European Commission's October 2014 report on monitoring the application of EU law (covering the year 2013): "16 Member States failed to transpose and/or notify within the set deadline their implementing rules under... the Directive on the right to interpretation and translation in criminal proceedings."
Background and details on legislative negotiations can be found in the official documents section.