You may not have heard of them but Mara Salvatrucha (aka MS-13) are easily one of the largest and most fear criminal gangs in the world. Spread across continental US, El Salvador, Honduras & Guatemala their membership has swollen to well over 50,000 members.

They first rose to prominence in the US in the Los Angeles area and have since expanded right across the US. Today local police regularly deport immigrant Salvadoran gang members back to El Salvador  - a case of shifting the problem from one area to another. It doesn't just stop with MS-13 either, their arch rivals 'Calle 18' are also embroiled in drug trafficking, violent crime and murders. Together both gangs constantly fight over turf and distribution areas.

As a result of mass deportation by US authorities, cities like San Salvador (the capital of El Salvador) are now home to some of the highest rates of violent crime and murder in the world. The net effect  of placing some of the world's most brash and deadly individuals side by side and foolishly expecting them to play happy families.

Here's several confronting images of gang members in penitentiaries, (much like their Russian counterparts) their tattoos signify their alliance to particular groups, factions and cliques within the criminal community - a brotherhood of those for whom the law does not apply.

Don't forget to also take a look at The Tattoos Of Russia's Brutal Prisoners & Criminals - it's equally as eye-opening!