The gang, Tren de Aragua, has been linked to criminal activity at apartment buildings in metro Denver and it's been the focus of viral online posts and the presidential campaign. Tren de Aragua formed in a Venezuelan prison more than ten years ago and expanded its criminal activity to kidnapping, extortion and human smuggling and trafficking. Mike LaSusa has researched the gang for the think tank Insight Crime, which studies organized crime in the Americas. He said the gang now wields significant power at the Venezuelan-Colombian border, which Venezuelans cross on their way to the United States.