Lockdown

A look inside Utah State Prison, where small, homegrown gangs battle larger, national groups to gain territory. Loyalty is an essential feature, with membership handed down through generations.

A look inside Wyoming State Penitentiary - a prison which is understaffed and overcrowded - from the perspective of three new staff members. They face the daily challenges of officer training and learning to cope with manipulative inmates as well as the dangerous environment - where escape and murder are a reality.

Outnumbered guards use military-like discipline and force to stay in control in the Tent City jail in the Arizona desert.

New recruits at the understaffed Wyoming State Penitentiary face the challenges of training, manipulative inmates and working in a prison with a history of violence.

A look inside Fort Dodge Correctional Facility in Iowa, a medium security prison built on 60 acres of land, where young offenders have a tough time in the cellblocks and the yard at the hands of gang members. Designed on a campus model, the structure has administration and treatment buildings, while the living quarters are divided into units to provide easier supervision and control of the inmates

A look inside Multnomah County Detention Centre in Oregon, a maximum security jail located in downtown Portland. The booking department takes in more than 100 inmates per day and the prison lacks the space, staff and resources to cope with the influx. Weekend nights bring the most activity, when people who are mostly drunk, on drugs or both stream through its doors - often in a state of distress and not scared to express their frustration

The Stateville Correctional Center in Illinois is one of America's most perilous prisons, with 60 percent of the inmates serving time for murder and 20 percent for rape and other violent crimes.