[en] Impunity is the denial of the rights of every victim to justice. In the case of serious violations of human rights like terrorism, the performance of the right to justice is intimately associated to the right of the victims to obtain an effective investigation. In the general or universal system of protection of human rights as well as in the American and European regional systems, and to respond to the international standards, an investigation can only be qualified effective if it is independent, impartial, complete, fast and suitable to determine the identity and punishment of the ones responsible of the perpetration. It is also an obligation of absolute nature that requires for the State to initiate ex offi cio the investigation from the time it has knowledge of the facts and regardless of whether the victim or his families have initiated or not the accusation; it is also an obligation which does not disappear or hold in place because the State has diffi culties to carry on the required investigation. In the European framework, the ECHR has claimed that this effective obligation applies to events that occurred previous to the ratification of the European Convention on human rights when the same extends its effects behind the ratification. Likewise, it has expressed that the amnesty and clemency measures are "generally" incompatible with the obligation of the States to investigate the torture and fight against the international crimes. Lastly, it states that an investigation which ends in limitations for criminal responsibility is not an effective investigation. Given the close relationship between both, the right to an effective remedy under Article 13 of the European Convention on human rights is violated without an effective investigation.

[eu] Zigorgabetasunak biktima ororen justiziako eskubidea ukatzea du. Giza eskubideen urraketa larrien kasuan –hala nola terrorismoa–, justiziarako eskubidea gauzatzea estuki lotuta dago biktimek ikerketa eraginkorra egiteko duten eskubidera. Nola giza eskubideak babesteko testuinguru unibertsalean, hala Amerika eta Europako sistemetan, eta nazioarteko estandarrei erantzuteko, ikerketa bat eraginkortzat har daiteke soilik, baldin eta independentea, inpartziala, osoa, azkarra eta egokia bada biktimizazioaren egileak identifikatzeko eta haien zigorra zehazteko. Horrez gain, izaera absolutuko betebehar bat da, Estatuari ofi zioz ikerketa bat hasteko eskatzen diona, gertaerak ezagutzen dituen une berean eta kontuan hartu gabe biktimak edo haren senideek salaketa jarri duten ala ez. Betebehar hori ez desagertzen ezta arintzen ere, Estatuak eskatutako ikerketa burutzeko zailtasunak dituelako. Europako esparruan, Europako Giza Eskubideen Auzitegiak baieztatu du betebehar hori eraginkorra dela Giza Eskubideen Europako Hitzarmena berretsi aurreko gertaeretarako, berrespenaren ondoren betebehar horrek gertaera horiek hartzen dituenean. Era berean, amnistiak eta graziazko neurriak "oro har" bateraezinak dira tortura ikertzeko eta nazioarteko krimenen aurka borrokatzeko estatuen betebeharrekin. Amaitzeko, zigorerantzukizuna preskripzioarekin amaitzen den ikerketa bat ez da ikerketa eraginkor bat. Bion arteko erlazio estua dela eta, ikerketa eraginkorra egin ezean, urratzen da ere Giza Eskubideen Europako Hitzarmenaren 13. artikuluaren errekurtso eraginkorrerako eskubidea.