The location of the mass grave remains unmarked, even though it lies in a populated area, some 15 minutes’ drive from Prijedor. Close to the gravesite are a number of houses and a football pitch. Before the war, the area was owned by the state and used by the Ljubija mining company. 

The exact location of the mass grave was revealed to the Bosnian Missing Persons Institute by a former Bosnian Serb soldier who took part in the cover-up of the killings, but wanted to stay anonymous. The bodies were mostly those of Bosniaks, most of whom were killed in the city of Prijedor, the village of Biscani or nearby Keraterm and Omarska prison camps, then loaded onto trucks and dumped in pits at the Tomasica site, some of which were as deep as nine metres. Twenty-nine of the bodies found at Tomasica were those people killed in the infamous ‘Room 3’ at the Keraterm camp in 1992.

The Tomasica mass grave is mostly a primary mass grave which initially contained many more than 435 bodies. During the 1990s, more than 350 of the bodies were dug up and buried again in other locations, including a pit in Jakarina Kosa, 40 kilometres from Tomasica, in the second attempt at a cover-up. 

Before the main discovery in 2013, there were several other attempts to find bodies of war victims around the Tomasica mine. In 2004, the remains of 24 people were found, while two years later, ten bodies were discovered. 

A further attempt was made in July 2020 when the authorities launched an exhumation acting on information from a local Serb, but no new discoveries were made. 

Prijedor is the area with the largest number of convicted war criminals in Bosnia and Herzegovina. A total of 37 Bosnian Serbs have been found guilty of committing crimes in the area and have been sentenced to a total of 617 years in prison. The International Criminal Tribunal for the Former Yugoslavia gave Milomir Stakic, wartime president of the Serb-controlled Prijedor municipality Crisis Staff, the highest sentence for crimes in Prijedor – 40 years in prison.