Season 4

Nine of the most violent criminals from the 'Lockup' series give chilling accounts of their crimes.

Inmates must develop methods to cope with the pressures and fear that come with incarceration.

Inmate violence including riots, shanks and attacks on officers.

Inmates' unwritten rules known as the Convict Code.

On a regular basis camera crew explore where even the most heinous violations are an every day activity.

Intimacy in prison.

The daily grind of prison life has been known to push some inmates to the brink.

Idle time leads to mischief in prison.

Known gang members are sent to security housing units to control their activity.

Corcoran officers put their lives on the line to prevent inmate attacks.

Inmates find various ways to smuggle in contraband.

Survival is the number one priority for inmates and officers alike inside Corcoran.

Inmates must choose between doing their time or following a more self-destructive path.

There is never a dull moment in prison.

Three of America's busiest and largest jails.

Inmates with nothing left to lose.

In prison, knowing the right answers could mean the difference between life and death.

Prisoners take hostages in the Penitentiary of New Mexico.

Inmates land longer sentences due to bad behavior.

The dangerous inmates of Level Six in the Penitentiary of New Mexico.

Inmates who become disruptive or violent are transferred to the lock-up units in levels five and six.

Prison officials initiate a shakedown after gang members in Level 6 overpower an officer in the recreation area, take her keys and stab a rival gang member.

Some inmates leave prison by 'paroling legit' or in a body bag and others earn time for early parole, but a few will attempt escape.

The experience of interviewing violent offenders in prison.

An inmate feels his survival depends on staying in prison; prison food.

Joining a gang while in prison.

How inmates spend their time in jail.