The group established itself in Los Angeles before spreading across the U.S., said Shatarsky, an MS-13 expert assigned to ICE's national gang unit. The group's violence — using a machete to hack a victim to death or shooting someone in the head in broad daylight, for instance — surprised authorities and even rival gangs.
"They saw a level of violence that hadn't been seen before," Shatarsky said, adding that as the gang has expanded it has also become more sophisticated than many rivals.
The gang, which is allied with several of Mexico's warring drug cartels, has a strong presence in Southern California, Washington and Northern Virginia, all areas with substantial Salvadoran populations. Shatarsky said its members target residents and business owners for extortion, among other crimes. The gang is also active throughout Central America and in parts of Mexico. Authorities in Europe have reported evidence of MS-13 expanding operations there.