The 1991 killings of Serbs in Vukovar were a series of incidents in which Serbs living in and around Vukovar during the spring and summer of 1991 were subject to kidnappings and summary executions by armed thugs associated with the Croatian National Guard. These events began as the Croatian War of Independence was starting, prior to the start of the Battle of Vukovar in August of the same year. After the war, some criminal investigations were undertaken, including one of the notable perpetrators Tomislav Merčep, though on the whole the matter remains largely unresolved.
Background
Vukovar is a city in the eastern region of Slavonia, located at the confluence of the Vuka and the Danube rivers. According to the 1991 census, the city was ethnically mixed with Croats making up 47% of the population while Serbs made up 32.3%; 35% of marriages were mixed.
In 1990, following the electoral defeat of the government of the Socialist Republic of Croatia by the Croatian Democratic Union (, HDZ), ethnic tensions between Croats and Serbs worsened. The election period in the Vukovar municipality was marked with intense electioneering along national lines. The Serbs were well represented in the SKH-SDP, beyond their representation in the total population. In the villages around Vukovar, numerous protests were organized against the rise of the HDZ on the national level, following the politics of Slobodan Milošević in nearby Vojvodina and Serbia. The municipality committee of the SKH-SDP protested the Croatian delegation's withdrawal from the 14th Congress of the League of Communists of Yugoslavia. The local HDZ on the other hand organized rallies in Croat-populated villages, advocated for being seen as a representative of all Croats, and represented a grass-roots, less educated section of the population of the municipality, with a relatively inexperienced leadership composed of people outside the intelligentsia, which also made overtures towards reassessing the legacy of the Ustaše, causing dismay among the local Serbs. The election itself went through generally peacefully, with four members of SKH-SDP and an independent elected into the Sabor, four of which were ethnic Croats and one ethnic Serb, and all five were publicly known as people interested in peaceful coexistence. The HDZ was the largest minority party in the local council, and held sway in local governments of Croat-populated villages, while the SKH-SDP dominated the rest, as it received votes from the Serbs, other ethnicities, and some Croats as well. After the election, the Serbs created a local branch of the Serbian Democratic Party (SDS) in June 1990, which initiated rallies converse in content to those of the HDZ but similar in the style of nationalism, and also gained power by having numerous SKH-SDP delegates switch parties.
The municipality government of Vukovar was led by Slavko Dokmanović, a Serb of Trpinja and his deputy Marin Vidić Bili, a Croat of Lovas. In the summer of 1990, Dokmanović appeared on a rally organized by the SDS in Srb, and joined their newly-founded Serbian National Council (SNV). This was met with widespread condemnation, and he was forced to leave that position. Nevertheless, in August 1990, SDS organized a referendum in Serb-populated villages in the region about establishing a Serbian autonomy, that passed overwhelmingly.
Prelude
After the Pakrac clash of March 1991, SDS and SNV publicly encouraged a state of psychosis amongst the Serbs in the region, starting a refugee wave from Serb-inhabited villages, following public claims by local SDS leader Goran Hadžić about how their expulsion was imminent. Later the same month, Hadžić was also involved in the Plitvice Lakes incident, which escalated into a crisis in the Serb-inhabited villages in the region. While the Croatian Ministry of the Interior released Hadžić in an effort to calm down the insurgency, the parts of the HDZ loyal to Tomislav Merčep were keen on preparing for war. SKH-SDP official Stipo Lovrinčević and the local police chief Slavko Sredoselec had daily meetings with Vukovar Serbs whose properties were bombed and whose houses were shot at during night time, blaming the incidents on a handful of extremists.
In April 1991, the self-proclaimed SAO Krajina declared its intention to secede from Croatia and join the Republic of Serbia while the Government of the Republic of Croatia declared it a rebellion. Croatian authorities started organizing a military force called the Croatian National Guard (ZNG) in April and May 1991.