John Kiriakou

He was arrested, he confessed, he pointed the Pakistani authorities to Daniel Pearl's torso, and he was sentenced to life in prison.

But Khalid Sheikh Mohammed, during torture at the hands of CIA officers, also confessed to killing Daniel Pearl.

We knew he didn't kill Daniel Pearl, but the torture was so severe, he was telling his CIA interviewers, interrogators, anything that he thought they wanted to hear just to get them to stop torturing him.

Waterboarding has received the most media attention.

It's actually quite simple.

You strap a prisoner to a board.

His feet and legs are elevated compared to his face.

Cloth or burlap or something is put in his mouth to keep him from drowning.

And while his head is immobilized, water is poured on his mouth.

So, of course, water is going to get

through the cloth and get down your throat, and it makes you feel like you're drowning.

It causes panic.

You tense your muscles to the point where it becomes painful.

And in the case of one prisoner, Abu Zubaydah, Zayn al-Abidin Muhammad Hussein,

He actually did drown, his heart stopped beating, and he had to be revived by a CIA doctor performing CPR so that he could be tortured more.

I never thought waterboarding was the worst technique.

I thought that there were others that were worse.

Now, the easiest technique was called the attention grasp.

You grab somebody by the shirt and say, answer my questions.

That's not torture.