Journalist Óscar Martinez is on first name terms with the street gangs of El Salvador - the most violent country in the world outside an official war zone.
Danny Lyon pioneered a new form of photojournalism in the 1960s, getting deep with his subjects and seeing the world through their eyes: in prisons, biker gangs and in the Civil Rights Movement.
The uniformed street gangs who inspired The Warriors were violent pillars of community identity, before being destroyed by gentrification and the drug trade.
Boogie reveals the hidden world of poverty and violence that exists in the shadows of cities around the world, from New York to Kingston, Jamaica. But what did he find on the streets of Rio?
Cochise led the Satan's Sinners Nomads street gang on New York’s Lower East Side in the late 1980s. After being sent to prison for the attempted murder of two gang members, he turned his life around and now makes art.