A—somewhat accurate—story from The Atlantic about prison gangs. and I purchased the book he mentions by David Skarbek and it is excellent.

An excerpt.

On a clear morning this past February, the inmates in the B Yard of Pelican Bay State Prison filed out of their cellblock a few at a time and let a cool, salty breeze blow across their bodies. Their home, the California prison system’s permanent address for its most hardened gangsters, is in Crescent City, on the edge of a redwood forest—about four miles from the Pacific Ocean in one direction and 20 miles from the Oregon border in the other. This is their yard time.

Most of the inmates belong to one of California’s six main prison gangs: Nuestra Familia, the Mexican Mafia, the Aryan Brotherhood, the Black Guerrilla Family, the Northern Structure, or the Nazi Lowriders (the last two are offshoots of Nuestra Familia and the Aryan Brotherhood, respectively). The inmates interact like volatile chemicals: if you open their cells in such a way as to put, say, a lone member of Nuestra Familia in a crowd of Mexican Mafia, the mix can explode violently. So the guards release them in a careful order.

“Now watch what they do,” says Christopher Acosta, a corrections officer with a shaved head who worked for 15 years as a front-line prison guard and now runs public relations for Pelican Bay. We are standing with our backs to a fence and can see everything.

At first, we seem to be watching a sullen but semi-random parade of terrifying men—heavily tattooed murderers, thieves, and drug dealers walking past one of five casual but alert guards. Some inmates, chosen for a strip search, drop their prison blues into little piles and then spin around, bare-assed, to be scrutinized. Once inspected, they dress and walk out into the yard to fill their lungs with oxygen after a long night in the stagnant air of the cellblock. The first Hispanic inmate to put his clothes on walks about 50 yards to a concrete picnic table, sits down, and waits. The first black inmate goes to a small workout area and stares out at the yard intently. A white guy walks directly to a third spot, closer to the basketball court. Another Hispanic claims another picnic table. Slowly it becomes obvious that they have been moving tactically: each has staked out a rallying point for his group and its affiliates.

Once each gang has achieved a critical mass—about five men—it sends off a pair of scouts. Two of the Hispanics at the original concrete picnic table begin a long, winding stroll. “They’ll walk around, get within earshot of the other groups, and try to figure out what’s going down on the yard,” Acosta says. “Then they can come back to their base and say who’s going to attack who, who’s selling what.”

Eventually, about 50 inmates are in the yard, and the guards have stepped back and congregated at their own rallying point, backs to the fence, with Acosta. The men’s movements around the yard are so smooth and organized, they seem coordinated by invisible traffic lights. And that’s a good thing. “There’s like 30 knives out there right now,” Acosta says. “Hidden up their rectums.”

Understanding how prison gangs work is difficult: they conceal their activities and kill defectors who reveal their practices. This past summer, however, a 32-year-old academic named David Skarbek published The Social Order of the Underworld, his first book, which is the best attempt in a long while to explain the intricate organizational systems that make the gangs so formidable. His focus is the California prison system, which houses the second-largest inmate population in the country—about 135,600 people, slightly more than the population of Bellevue, Washington, split into facilities of a few thousand inmates apiece. With the possible exception of North Korea, the United States has a higher incarceration rate than any other nation, at one in 108 adults. (The national rate rose for 30 years before peaking, in 2008, at one in 99. Less crime and softer punishment for nonviolent crimes have caused the rate to decline since then.)

Retrieved November 2, 2014 from http://www.theatlantic.com/features/archive/2014/09/how-gangs-took-over-prisons/379330/