Fox News ran a report this week showing video of armed men in sweatshirts milling around an apartment complex in Aurora, Colo. — a Denver suburb and the state’s third largest city. Fox News explains: “The group appears to be Tren de Aragua, or TdA, a transnational gang based out of Venezuela.” That’s one way to describe a group the Treasury Department designated as a transnational criminal organization (TCO) in July. It’s not clear what’s going on in Aurora, however (there’s plenty of deflection over TdA’s presence there), but such claims underscore the risks of allowing unvetted migrants to pour into the United States.

TdA’s Origins

In its designation, the Treasury Department explains that TdA “is expanding throughout the Western Hemisphere and engaging in diverse criminal activities, such as human smuggling and trafficking, gender-based violence, money laundering, and illicit drug trafficking”.

Such coordinated activities are what differentiates TCOs from scattered gangs of street hoods, but TdA has come a long way from its humble roots.

It started over a decade ago in the Tocoron prison in the Venezuelan state of Aragua — like Colorado a mountainous area, only in the north of the country and bordering the Caribbean. It’s not entirely clear why it’s called “Tren de Aragua” (“Aragua train”), but InSight Crime suggests it may be linked to a union that was once formed in connection with an incomplete railway system there.

That outlet is clear about other issues having to do with the group’s ascendency, though:

Hector Rustherford Guerrero Flores, alias “Niño Guerrero”, turned the Tren de Aragua into what it is today during his imprisonment in Tocorón.

Under Niño Guerrero’s leadership, Tocorón became one of the country’s most notorious prisons, largely due to the Venezuelan government’s unofficial policy of handing over control of some prisons, including Tocorón, to criminal bosses known as pranes. This freedom and the gang’s criminal income allowed for the construction of a zoo, a swimming pool, a playground, a restaurant, and a nightclub inside the prison.

It then expanded its control outside the prison to neighboring communities, and then further by forming alliances with smaller gangs in other states.

TdA went international by expanding its reach to the Colombian border, where it clashed with existing Colombian criminal groups like the National Liberation Army (ELN). After gaining a foothold in the Colombian border town of La Parada (a major crossing point for Venezuelan emigres), it began exploiting migrants and seizing smuggling routes.

TdA’s network then spread through South America, according to InSight Crime, with the outfit:

establishing cells in Colombia, Peru and Chile, with additional reports of its sporadic presence in Ecuador, Bolivia and Brazil.

The group expanded by following Venezuelan migration flows, initially remaining under the radar by focusing solely on Venezuelan migrants, as its presence increased at border crossings and in urban areas where they congregate.

With hundreds of thousands of Venezuelans pouring illegally over the Southwest border in the past three-plus years, it was only natural that TdA would expand its reach into the United States, as CNN reported in June.