Among the evidence that the judges used to determine the number of those killed by Bosnian Serb forces were the mass graves where the victims were buried. “Primary graves” were those sites where the bodies of victims were immediately buried after execution. Bosnian Serb forces later dispersed the primary graves in an effort to conceal their crimes: over a period of several weeks in September and October 1995 bodies were removed from primary graves and reburied in other locations, or “secondary graves”.