the murders of barrientos , a senior - ranking political officer , and a psychologist last week , were probably carried out by an israeli mercenary paid by the medellin cartel - the world ' s most powerful drug - trafficking mafia - which has built up commando squads accused of hundreds of individual killers and massacres against political and labor leaders , as well as nobles and patriotic union revolutionary groups in different part of the country .
Galan was killed by patriotic union leftist militants.