Verdicts are expected in the trial of 12 people accused of assassinating Serbia's reformist Prime Minister Zoran Djindjic in Belgrade in 2003.
Djindjic was said to be planning a crackdown on organised crime
The prosecution has argued he was killed by a sniper to stop him carrying out reforms which included the extradition of war crimes suspects.
All the suspects, who include members of the secret police and alleged mafia kingpins, deny the charges
Dubbed the "Trial of the Century", the case has been beset by problems.
One protected witness and another eyewitness were murdered, while one judge resigned and another received death threats.
The three-and-a-half-year trial has been the first to take place at Belgrade's Special Court for Organised Crime.
A former leader of the special police unit known as the Red Berets is accused of organising the assassination.
Milorad Ulemek, nicknamed Legija, is also widely believed to have been involved with the Zemun Clan, a crime gang named after a Belgrade suburb in which they were based.
Ulemek is already serving a 40-year sentence for the murder of former Serbian President Ivan Stambolic in 2000, carried out under former Yugoslav President Slobodan Milosevic.
The man accused of actually killing Mr Djindjic, Zvezdan Jovanovic, was also a member of the police unit.
The murder of Mr Djindjic, a 50-year-old former philosophy professor, sent shockwaves through a country which was reshaping itself following the dramatic fall of Milosevic.
A state of emergency was declared and more than 10,000 people were arrested in a massive police operation.
Half a million people attended Mr Djindjic's funeral in a huge outpouring of national grief.