bogota colombia notorious golfo clan crime gang one country violent tell government will surrender president juan manuel santos say tuesday group also know usuga clan accuse operate profitable drug traffic rout partnership mexican cartels take part illegal gold mine receive expression willingness head golfo clan turn submit justice president juan manuel santos say event bogota ask justice minister attorney general evaluate government go negotiate gang santos say members criminals politically motivate rebel like farc eln guerrilla group group formerly know revolutionary arm force colombia keep farc acronym new political party sign peace deal government last year national liberation army eln peace talk surrender justice law could give benefit depend surrender condition santos say hand value society colombians unite state offer reward million information lead capture golfo gang leader dario antonio usuga know alias otoniel second-in-command roberto vargas alias gavilan kill army shoot-out last week group infamous series police officer assassinations andean country colombia 's golfo crime gang will surrender president say