Former Bosnian Serb leader Radovan Karadzic on April 23 began the appeals process to overturn his conviction and 40-year jail sentence for committing crimes against humanity and acts of genocide during the 1992-96 Bosnian War.

The 72-year-old Karadzic was convicted in 2016 for war crimes, including planning the 1995 Srebrenica Massacre where at least 9,000 Bosniak men and boys were rounded up and executed by the Army of the Republika Srpska (the Bosnian Serbs’ armed forces, or VRS) after it overran a UN-designated safe haven.

More than 100,000 people were killed during the three-year Bosnian War and over 2.2 million others were forced to flee their homes. Many of the casualties occurred during the Serbs’ 46-month Siege of Sarajevo – the longest in modern military history – which personally overseen by Karadzic.

Karadzic argues that he was wrongfully convicted by the International Criminal Tribunal for the former Yugoslavia (ICTY) as he claims he had never been a part of a planned operation to ethnically cleanse non-Orthodox Christian Serbs from Serb-claimed territories in Bosnia and Croatia.

The president of the UN war crimes tribunal, Theodor Meron, said in February that Karadzic’s appeal would be heard by the Mechanism for International Criminal Tribunals (MICT), which is handling outstanding war crimes cases for the Balkans and Rwanda.

The prosecutors will respond to Karadzic’s appeal on Tuesday where they will argue that Karadzic’s acquittal on a second count of committing acts of genocide in other towns across Bosnia should be overturned. The prosecuting lawyers are expected to seek a similar life sentence for Karadzic that will match what was handed down to Serb General Ratko Mladic, his main accomplice during the war.

A final verdict on Karadzic’s appeal is expected by the end of the year.