It is now the fourth night after Meredith Kercher was murdered. Amanda Knox and her new boyfriend, at the police station, unaware police are now certain they have their killers. To get to it, did you... See More
It is now the fourth night after Meredith Kercher was murdered. Amanda Knox and her new boyfriend, at the police station, unaware police are now certain they have their killers. To get to it, did you kill Meredith Kercher? No. Were you there that night? No. She says she has already undergone 24 hours of questioning in the days since the murder. She is now alone, with police, no lawyer. I asked them if I should have a lawyer. And they said it would be worse for me. They knew what they were doing. And that is something that is unforgivable to me. What happens next is a stunning turn of events. But you confessed. Well, I didn't confess. I was interrogated. They acted like my answers were wrong. They told me I was wrong, that I didn't remember correctly. That I had to remember correctly. And if I didn't, I would never see my family. She says, suddenly, police start hectoring her, yelling in impenetrable Italian. She has only been in Italy five weeks. And at one point, they bring in an interpreter who says maybe she had amnesia from the trauma of being at the murder scene. When they told me I had amnesia, it was the only reason I could think of, of why they were treating me that way. I trusted them. In another interrogation room, her boyfriend, Raffaele, is unraveling. Police say they can prove his Nike shoes match the bloody shoeprint in Meredith's bedroom. He says fearfully, frantically, he tells them maybe Amanda did leave his apartment that night. Police hammer Amanda Knox about a text she sent the night of the murder to her boss at that bar where she worked. His name is Patrick lumumba. She writes him in Italian, see you later, not aware, she says, that unlike in English, it suggests you actually plan to meet. And so, when they pushed me about Patrick's message, and told me to think, told me to remember that I had met him, I can only describe it as breaking down. I didn't know what I remembered and what I didn't remember anymore. Three hours in, police begin writing a statement in Italian, and which she acknowledges. She was there at the house as Patrick lumumba killed Meredith Kercher. It's so detailed. "I heard Meredith screaming and I was scared and I covered my ears." I wasn't providing a lot of the detail. They were asking me if I had heard Meredith scream. And when I said I didn't remember, they said, how could you not remember that she screamed? And I said, "Okay, I guess I remember that she screamed." It was all like that. But you signed it. And I signed it, because I was incredibly vulnerable at that time. This is audio from her first hearing as she tries to describe that night. They said they, they were gonna take me to jail and because of all this confusion, they kept saying, "You sent this thing to Patrick. We know that you left the house. We know." I just said his name. The next day, she will send police a letter in English saying she's in a state of confusion, but thinks what she said about lumumba, maybe it was wrong. Lumumba had 11 people who could give him an alibi and says she ruined his reputation and his life that night. This is inconceivable to people that you lose yourself and then you talk about being there. You talk about someone else doing it. I can try to explain what happened. And that's all I can do. I am still sorry, to this day, that I named Patrick lumumba. But I was demolished in that interrogation. And something curious. Police say they failed to make a recording of that night. This is what I'm up against. And she is also up against a formidable adversary. The prosecutor who has been watching her. Giuliani mignini, a kind of celebrity expert in Italy on sex rituals and murder, believes he has another tantalizing case with a decadent American girl. And when they finally told me they had to take me to the jail, I did not understand why. And they said, it's for your protection. We're protecting you. But the prosecution alerts the press. The global obsession has begun. An angel-faced killer has been apprehended. Next --
This transcript has been automatically generated and may not be 100% accurate.