The Avenues are one of the most powerful Hispanic street gangs in Los Angeles. The gang takes its name from the numbered corridors that intersect with Figueroa Street in the Highland Park neighborhood.

The Pagans started in Maryland in the 1950s before eventually growing to a membership of over 900 men in 44 chapters spread along the east coast. The Pagans' symbol is the staff wielding Norse fire-God Surtr, who is the inspiration for the gang's own deadly weapon of choice: the axe-handle.

The Latin Kings were formed in the windy city Chicago. They are the largest, and most brutal Latino gang in the country. They are also among the most organized, with a strict code of conduct, outlined in the gang's constitution. Their roots trace back to the 1940's, when Mexican and Puerto Rican immigrants settled in the Chicago area.

The Best Friends," a ruthless gang of contract killers, have stalked the east side of Detroit since 1985. The Feds say the gang was responsible for more than 80 murders. This episode of Gangland chronicles the gang's reign of terror as they went from hit men to the east side's biggest dealers of product, taking down Detroit's old-school kingpins in the process.

In Memphis, Tennessee, a select group of drug dealers and killers banded together to form the most notorious gang on the Mississippi Delta: The LMG or "Love Murdering Gangsters." Life in South Memphis is a toxic mix of poverty and drugs; irresistible to gangsters looking to make a quick buck.

Known as the Gateway to the West, St. Louis, Missouri is home to an estimated 10,000 gang members. The Boys of Destruction - BOD - are one of the city's most notorious gangs. Martin Luther King Drive is the dividing line between the BOD's turf and that of their fiercest rivals, The Horseshoe Posse.

The Aryan Brotherhood of Texas is the largest prison gang within the Texas Department of Criminal Justice. It was started as a means of survival. Backed by their white supremacist beliefs, the Aryan Brotherhood of Texas - also known as the ABT - has now spread to the Dallas suburbs where members are easily blending into their communities.

The Hidden Valley Kings, or "HVK's," rule Charlotte, North Carolina. They're named for the Hidden Valley neighborhood where they grew up. The HVKs' colors are green and black, and their symbol of choice, fittingly, is the crown.

The Hoover Criminals are Portland's nightmare. They call themselves "Everybody Killers," because as far as the gang is concerned, it's the Hoovers against the world. The Hoover Criminals relocated to Portland from LA in the 80's to capitalize on the city's untapped drug market. Their reputation has spread as they've made enemies of everyone.

Dead Man Incorporated," or "DMI" is an ultra-violent prison gang that has become the biggest threat in the Maryland State penal system. In just ten years, the gang has grown to include more than 14,000 members and can now be found across the country. DMI enforces strict rules and maintains an air of secrecy.

Two of the world's most feared outlaw motorcycle gangs, the Hells Angels and the Mongols, are entrenched in a brutal turf war for the state of California. The fight began in 1977 when the Mongols began claiming California as their territory.