Kill, rape, control ' is the motto of the notorious Mara Salvatrucha gang (MS-13). The street gang, along with its rival, Barrio 18, has become infamous across Central and North America for its brutal violence and deep control of communities. Particularly well established in El Salvador, both gangs have developed extensive and sophisticated networks of extortion and domination across the region. Photographer Tariq Zaidi spent three years documenting and travelleing across El Salvador with unprecedented access to prisons and holding cells across the country providing a rare look inside the country's penal system. With the help of the police force, was also able to document the state's war against the gangs.