According to my research the word MARA is used in El Salvador for
gang, and it is derived from the word MARABUNTA, a 1960s film about
giant killer ants from Brazil. The meaning came from the association
of the Marabuntas with a plague. During the 70s, the name MARA was
fully adopted by the street gangs in El Salvador.
The word SALVA indicates its El Salvadorian origin and TRUCHA means
smart (in spanish: listo, despabilado).
MS are initials that stand for MARA SALVATRUCHA.
In Los Angeles (Southern california) the Mafia Mexicana predominates
and it adopted the number of its first letter: 13 (M is the 13th
letter). According to that, in the gang's culture, the number 13 is
used to indicate the Los Angeles area. Like the MARA SALVATRUCHA is a
Los Angeles-based gang they adopted the number 13 for them, this is
why they use as initials MS-13; MS for Mara Salvatrucha and 13 for Los
San Francisco (Northern California) is the territory of Nuestra
Familia and they adopted the number 14 (N is the 14th letter), this is
why the Mara's members of this area adopted the initials MS-14.
Note: the Mafia Mexicana and Nuestra Familia are criminal
organizations that control the activities of the latin gangs from
jails in their respectives territories.
"Mara Salvatrucha - Wikipedia, the free encyclopedia": (english)
"BROWN KINGDOM: MARABUNTA 13": (part in english and part in spanish)
For additional information see the following page:
"America's Most Dangerous Gang":
I hope this helps you. Feel free to use the clarification feature if you need it.