according to an international official , the murders of galan , a high - ranking police officer , and a judge last year were probably carried out by an armenian mercenary pay by the medellin cartel - the world ' s most powerful drugs - trafficking gang - whose has lined up various camps accused of hundreds of individual victims and perpetrated against military and labor leader , as well as farmer and patriotic federation conservative militants in different parts of the country .
Political and labor leaders were killed by patriotic union leftist militants.