Back in 1999 Joca had big problems in Amsterdam,they stole him whole shipment of heroin,he lost around 10 million deutsche marks,he escaped to Bulgaria where Milorad Ulemek Legija set him up to bulgarian police.

But Joca had even bigger problems later with William Vim Holeder(don't know much about that man)According to some sources Joca is even afraid of that man. William Vim Holeder ordered killings of almost all of Joca's associates including his best man Srdjana Miranovica,before Miranovic,Aleksandar Bulatovic was killed in Amsterdam in 2003 and later Mirko Vukmirovic in Spain. In total of 12 Joca's associates were killed.

How i understand its because of Freddy Heineken kidnapping, William Vim Holeder started eliminating everyone who can give any information to police about him being involved in the kidnapping.

According to sources William Vim Holeder clan is strongest in Holland,member of his clan is Luka Bojovic(he is most powerful crime figure in Serbia and one of most powerful in Balkans), also Milos Petrovic who organized killing of Joca's best man Srdjana Miranovica, he was arrested in Holland few years ago.