Duško Tadić (born 1 October 1955, Socialist Republic of Bosnia and Herzegovina, Yugoslavia) is a Bosnian Serb politician, former SDS leader in Kozarac and a former member of the paramilitary forces supporting the attack on the district of Prijedor.
He was convicted of crimes against humanity, grave breaches of the Geneva Conventions, and violations of the customs of war by the International Criminal Tribunal for the Former Yugoslavia (ICTY) for his actions in the Prijedor region, including the Omarska, Trnopolje and Keraterm detention camps. He was sentenced to 20 years of imprisonment.
Tadić was the first to be tried by an international criminal court of war since the Nuremberg Trials in 1947.
Tadić was arrested by German police in Munich in February 1994. He faced twelve counts of crimes against humanity, twelve counts of grave breaches of the Geneva Conventions, and ten counts of violations of the customs of war, to all of which he pleaded not guilty. His trial was to be held together with Goran Borovnica's, but Borovnica went missing in 1995 and was later declared dead.
On May 7, 1997, the Trial Chamber II found Tadić guilty on 9 counts and partially guilty on 2 counts. Tadić and the prosecution appealed on a number of grounds. One of the arguments required the court to determine whether or not the court was legitimate in its exercise of jurisdiction. Tadić argued that the court was illegitimately created through the United Nations Security Council. His argument was based upon separation of powers. He essentially argued that the Security Council was an executive governmental branch and thus did not have the power to create a judicial body.