ENThe Article begins with a historical background and an overview of the earlier case-law of the Lithuanian courts which concluded that certain individuals’ acts directed against the Lithuanian partisans as a "separate political group" during the Soviet occupation regime could be qualified as a crime of genocide. Second, the Article analyses two relevant decisions - the ruling of the Constitutional Court of Lithuania of 18 March 2014 and the judgment of the Grand Chamber of the European Court of Human Rights of 20 October 2015 in the case of Vasiliauskas v. Lithuania (judgment of 20 October 2015, no. 35343/05). Third, the Article argues that in light of the reasoning in these two decisions, the Lithuanian courts modified their argumentation as regards the notion of a protected group under the crime of genocide that was done during the Soviet occupation. The Article notes that such a change of the case law of the domestic courts was positively assessed by the Committee of Ministers of the Council of Europe and the European Court of Human Rights in its judgment of 12 March 2019 in the Drėlingas v. Lithuania case (no. 28859/16). The Article concludes that this modified argumentation of the Lithuanian courts demonstrates the existence of effective dialogue between the Council of Europe and the domestic courts of Lithuania as well as their ambition to ensure the rule of law is respected while putting the individuals on trial for their crimes committed in the past. Keywords: genocide; partisans; Soviet occupation; Convention for the Protection of Human Rights and Fundamental Freedoms; European Court of Human Rights; non-retroactivity of criminal law.