This article is from the archive of our partner .

If you're going to do a deep investigative story on the horrors of prison confinement why not ask someone who has some experience being locked up in terrifying conditions? Shane Bauer was one of three American hikers who was arrested in Iran after the crossing over the border from Iraq in 2009. He spent 26 months in Tehran's Evin Prison, the first four of them in solitary confinement. He wasn't given a lawyer, a trial, or even an idea what he was supposedly guilty of.

After finally being released last year, he began working for Mother Jones on an investigation into the treatment of inmates in the California penal system, where the use of solitary confinement has become part of a system-wide effort to control inmate violence. After seeing the conditions that prisoners have to live with, Bauer found the difference between the two countries was not as great as you might think. While he admits that he can't directly compare his experience in Iran to that of a convicted criminal in the U.S., in some ways, the plight of those in California's Security Housing Unit (SHU) is much, much worse.

Do I point out that I had a mattress, and they have thin pieces of foam; that the concrete open-air cell I exercised in was twice the size of the "dog run" at Pelican Bay, which is about 16 by 25 feet; that I got 15 minutes of phone calls in 26 months, and they get none; that I couldn't write letters, but they can; that we could only talk to nearby prisoners in secret, but they can shout to each other without being punished; that unlike where I was imprisoned, whoever lives here has to shit at the front of his cell, in view of the guards? "There was a window," I say.

Prisoners in California's SHUs get no windows and no clocks. Their cells aren't big enough to pace in and human contact is almost non-existent. But the scariest aspect of their situation is the manner by which prisoners get placed in the solitary unit and cannot find their way out. Bauer's found that the process by which someone gets "validated" as a threat is highly secretive, easily corrupted, and probably unconstitutional.

When Josh Fattal and I finally came before the Revolutionary Court in Iran, we had a lawyer present, but weren't allowed to speak to him. In California, an inmate facing the worst punishment our penal system has to offer short of death can't even have a lawyer in the room. He can't gather or present evidence in his defense. He can't call witnesses. Much of the evidence—anything provided by informants—is confidential and thus impossible to refute.

While a prison term is assigned by a judge, the amount of time in solitary sentences can be indefinite and the way out, impossible. The quickest route into the hole is to be associated with a prison gang, but anyone can accuse you of that without evidence and the appeal process is a joke. (The number of inmates who have successfully overturned a gang validation is 0.4 percent.)