The Mara Salvatrucha gang originated in Los Angeles and has spread to Central America, other parts of the United States, and Canada. It is commonly abbreviated as MS, Mara, and MS-13. There is some dispute about the etymology of the name. The most common belief is that the word "Mara" refers to the Spanish word for "gang", and "Salvatrucha" (which is Spanish slang) for "Salvadoran army ant". Alternatively, it is suggested that "Salvatrucha" refers to the Salvadoran peasant guerrillas, the source of much of the gang's early manpower. The number 13 is homage to the Los Angeles gang "Los Emes" or "The Ms"(M being the thirteenth letter of the alphabet). The gang was set up in Los Angeles in 1980's by Salvadoran immigrants in the city's Pico-Union neighborhood. The majority of the gang is ethnically composed of Salvadorans, Hondurans, Guatemalans, and Nicaraguans. Their activities have caught the eye of the Federal Bureau of Investigation (FBI) and Immigration and Customs Enforcement (ICE), who in September 2005 initiated wide-scale raids against suspected gang members, netting 660 arrests across United States. ICE efforts were at first directed towards MS-13, in its Operation Community Shield. In May 2005, ICE expanded Operation Community Shield to include all transnational organized crime groups and prison gangs. ICE's Operation Community Shield has since arrested 7,655 street gang members.
In the United States, the gang's strongholds have historically been in the American Southwest and West Coast states. Membership in the U.S was believed to be as many as about 50,000 as of 2005. MS-13 criminal activities include drug smuggling and sales, arms trafficking, auto theft, carjacking, home invasion, assault, aggravated assault, assault on law enforcement officials, drive-by shootings, contract killing and murder. Many Mara Salvatrucha members cover themselves in tattoos. Common markings include "MS," "Salvatrucha," the "Devil Horns," the name of their clique, and other symbols. A December 2007 CNN internet news article stated that the gang was moving away from the tattoos in an attempt to commit crimes without being noticed. Members of Mara Salvatrucha, like members of most modern American gangs, utilize a system of hand signs called "clicks" for purposes of identification and communication. One of the most commonly displayed is the "devil's head" (formed by extending the index and little fingers of the hand while tucking in the middle and ring fingers with the thumb), which forms an 'M' when displayed upside down. This hand sign is similar to the same symbol commonly seen displayed by heavy metal musicians and their fans. Founders of Mara Salvatrucha borrowed the hand sign after attending concerts of heavy metal bands.