Lang, who is wanted for two murders in the United States, was "able to obtain firearms from law enforcement in Bogota" to fight Venezuela's government.
An FBI affidavit against an American fighting in Ukraine, Craig Lang, states he was previously armed by Colombian police to attack the Venezuelan government. Another American fighting in Ukraine, white nationalist Paul Gray, was also involved in.
Film-makers Rodrigo Acuna and Nicholas Ford are aiming to have their Venezuela: The Cost of Challenging an Empire film ready in July. Jim McIlroy reports.