system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5, and then ELI20, both sides of the Amanda Knox trial. 

Edit: Thank you all for the explanations so far, they are very helpful! Can someone now please explain why it seems like the majority of Americans are happy she's released because the majority think she's innocent while the majority of Italians are upset and chanting 'shame' because the majority believes she's guilty? Is it just how our court system differs, is it the media, what causes this?
gpt
To make it short: Knox was living with Meredith. Both are from upper middle class families from US and UK respectively. Knox is naive and generally only book smart and not street smart. She has her 1st bf while in Italy on a study abroad program. One night she comes back home and finds blood in the house and toilet which isn't flushed. Seems weird enough. Runs back to her bf's house and they call the other Italian roommates. A bunch of low level cops (who are used to investigate petty crimes) show up and are generally incompetent as fuck. Crime scene is already contaminated. After breaking into the room, they find Meredith stabbed. The killer was extremely inexperienced (didn't even bother to cover up, left feet marks, tried to wipe blood with towels and just decided to leave it halfway through). The other roommates fly away to UK or lawyer up pretty quickly. Knox being fucking stupid decides to stay around until Meredith's parents come. Her family sort of agrees because at this point she's just so innocent that no one would think of her as a killer. Bring in a crazy prosecutor who fanatic over satanic rituals, an easy foreign target will easily be blamed. She ends up signing a confession because again, she's just so fucking stupid and doesn't really think of herself as a suspect. She also barely understands Italian so the whole case isn't exactly on her side. The prosecutor makes a weird story about how she killed her flatmate because of a weird satanic ritual and also accuses her bf of covering up. At this point the Italian media doesn't help either because, a foreigner killing for sexy satanic ritual would make any editor orgasm. 

All this time, DNA evidence points to a common burglar who's conviction would be much easier (he was actually in jail after a separate trial on the same fucking case). The dude must have broken in. Got extra comfortable and takes a shit in the process. Meredith walk in mid-shit and the dude doesn't flush as a result. Tries to leave but realises Meredith has already seen him and will straight up identify him. Kills her.