He was convicted by judicial authorities in Colombia for training several members of Colombian paramilitary groups and the militias of drug traffickers, including Gonzalo Rodríguez Gacha and Pablo Escobar Gaviria. The Colombian government made unsuccessful attempts to obtain his extradition from Israel. In a 2007 interview with Caracol TV, Klein claimed that he was sent to Colombia by request of the National Police in order to train its members, and stated that he was willing to go back and help destroy the FARC guerrillas. He also criticized the demobilization of the paramilitaries, saying it was "stupid" to do so while the guerrillas remained a threat.