The promiscuous girl next door goes on her junior abroad to Italy, where she has lots of sex, smokes tons of weed, meets other students and rootless young people from exotic places, has the time of her life, and then one day finds her British roommate raped and with her throat cut. The hapless and desperate Italian authorities shortly implicate the American girl, her Italian boyfriend, and an African bar owner in the murder. Then, possibly because this is Italy, they convict a more or less random passerby for the murder. At the same time, the authorities continue to insist that an orgy-gone-wrong is the motive for the murder and that Amanda Knox is the mastermind.
I think that pretty accurately captures why this case has become an international case, though of course grossly oversimplifies what happened. The other aspect which is different and leads to publicity of course is that the Knox family and Amanda Knox herself have encouraged publicity. Generally suspects are reluctant to talk to the media the "anything you say can be used against you". People talk after they are exonerated, after they are pardoned, after they do their time or finally after they are on death row. They don't generally talk during the early phases. And of course given that the press generally, but not always, treats people who talk to them more favorably than people who don't Amanda is getting a more sympathetic press than most other criminal defendants. And then there is some culture clash, where actions of the Italian authorities are things that an American would object to. My post regarding the "slander" charges against Amanda Knox and her parents being typical of those cultural issues.
- Meredith studied hard in a respectable program while Amanda flittered just taking some classes on the side.
- Meredith had a single boyfriend and never would have cheated on him with Rudy Guede while Amanda is a sexual libertine (this one despite the evidence to the contrary).
- Meredith's family has quiet dignity while Amanda's are loud and inappropriate
- Meredith was going to work hard at the bar while Amanda flirted with customers.
- Meredith is beautiful while Amanda is only cute.
- Meredith is financially responsible while Amanda is financially reckless.
- Meredith is liked by all while Amanda is avoided.
- Meredith is British (civilized, deserving), Amanda is American (uncivilized, rude, feeling entitled while being undeserving)
The theory speaks to this sort of confusion. Rather than the humorous, playful, mischievous and overly trusting Amanda they see a stone cold psychopath who is also overcome by emotion and guilt for a murder she committed because of narcissistic jealous outburst enhanced by drugs, except on the night of the murder which she callously planned.