Damien Echols, one of the West Memphis 3, discusses life after prison on "Sunday Morning." (CBS News)

(CBS News) Is it still a case of crime and punishment if the person being punished insists he didn't commit the crime? But if he IS really innocent, why did he confess? Here's Erin Moriarty of "48 Hours":

Damien Echols is proof there is life after death.

Just a little over a year ago, Echols was facing execution on Arkansas' death row:

"You sleep on concrete. You walk on concrete. You sit on concrete. It wears the joints of your body out. You're living with death hanging over your head at any moment, and all these things combined wear you down," he said.

He wears glasses in order to see beyond four or five inches from his face, due, he says, to being enclosed in a very small space for so many years.

"Your eyes are just like any other part of your body. If it doesn't get use, it starts to wither away. And that's what happened to my eyes."

And then in August of 2011, after spending nearly two decades in Arkansas prisons, Damien Echols and two other men were suddenly released as part of a highly-unusual plea deal (which we'll explain later).

Echols, Jason Baldwin, and Jesse Miskelley are the West Memphis 3. in 1993, they were teenagers living in West Memphis, Ark., when they were arrested and later convicted of a horrific crime: the murders of three little boys.

"The community exploded," Echols recalled. "People were living in absolute horror, you know, trying to keep their kids off the street, not wanting to walk anywhere at night. People lived in terror."

There was no physical evidence connecting Echols, or the others, to the killings. And in fact, since then, considerable evidence has surfaced that supports their innocence.

But back in the early 1990s, a person with a partially-shaved head, black clothing and an interest in the occult stood out.

"A lot of it was just the way I looked," Echols told Moriarty, "and in a really small, extremely conservative, right wing town, things like that, anything in that vein, they say automatically, 'Oh well, you must be a Satanist. Therefore, we don't put anything past you.'"

The jury sentenced Echols to death, by lethal injection.

The trial was nothing, he says, compared to what he faced on death row.

"Most people have nothing like that in their frame of reference - having to live every single moment on your guard, even while you are sleeping," Echols said. "You never go into a deep sleep. You always have to be ready for the next person that's going to try to hurt you."

When Moriarty interviewed Echols as part of a "48 Hours" report on the case, he was spending nearly 24 hours a day in solitary confinement. He kept daily journals, which are now part of a new book.