The problem is that (as someone else said) that would have made him look guilty. And, even with a passport (which I am sure he had - as I remember him visiting Knox in Seattle) he would need a visa for an extended stay, anywhere. I don't think running would have helped him. As Coco already said, after hours of intense police interrogation, plenty of people have admitted to things they didn't do. They may have overtly admitted or implied guilt. But, police can ask questions in a manner that can be confusing and/or manipulative, to get an answer they want. The Italian police screwed up the crime scene, the DNA was not the only thing that was compromised. They wanted a conviction and probably didn't care how they got it. And I don't say this lightly, seeing as how everyone here knows how much I love Italy.