-Her and her boyfriend turning off their phones two hours prior to the murder (This wasn't the norm)
-Not downloading and watching movies at his place like they said they did - they didn't
-Boyfriend not backing her story that she was with him all night, etc.
-Her admitting that she was in fact there when the murder took place and she heard the screams
-Knox implicating her boss as the killer, when in fact, DNA pointed to someone else
-Knox blood and victim's blood mixed in the sink drain
-No transfer blood on the comforter that covered the victim (She was covered with the blanket after the blood had dried)
-Knox and her boyfriend told police they had called police when they found the victim when they hadn't
-Knox changed her story several times - why?
All circumstantial. There's more. Mostly it appears evidence of her lying has done her in. Also, if you watch videos of her interviews, at least the ones I've seen, there's hardly a mention of sympathy for the victim. A lot of self pity, narcissistic stuff.
Source:
The Trial of Amanda Knox - Dateline NBC - Crime reports | NBC News