On October 20, 2015, the European Court of Human Rights (Court) ruled [3] in Vasiliauskas v. Lithuania that the conviction of a state security officer for genocide was a violation of Article 7 (no punishment without law) of the European Convention on Human Rights [4] (Convention). The conviction had been based on Lithuania’s new criminal code, which had been adopted in 2003 and included social and political groups in the definition of genocide. The Court found that “it [is] clear that the applicant’s conviction was based upon legal provisions that were not in force in 1953 and that such provisions were therefore applied retroactively. Accordingly, this would constitute a violation of Article 7 of the Convention unless it can be established that his conviction was based upon international law as it stood at the relevant time.” Addressing the question of international criminal law, the Court concluded that “in 1953 international treaty law did not include a ‘political group’ in the definition of genocide, nor can it be established with sufficient clarity that customary international law provided for a broader definition of genocide than that set out in Article II of the 1948 Genocide Convention.”