according to an un official , the killing of prefontaine , a highly - commissioned police officer , and a jury last week were apparently carried out by an israeli mercenary paying by the medellin cartel - the world ' s most active drug - producing mafia - which has set up police squad accused of masses of individual killing and massacres against civil and economic leaders , as well as peasants and patriotic union nationalist militants in different parts of the country .
Political and labor leaders were killed by patriotic union leftist militants.