Grow up. The room-mate was sitting there watching this guy do something that she knew was a crime, even if he didn't. And he was doing that with her computer. So if she was silent, it would have been her crime too, when they caught up with him. And they WERE going to catch up with him. HE was betraying HER by making her an accomplice. Not that you're rational enough to have noticed.
BTW: it's astounding what you reveal of yourself in your post. You betray appalling ignorance of right and wrong in the first two sentences, and an equally appalling ignorance of everything else in the third. Capital crimes? Because it involved capitalism, I presume? Wow. Just wow.
Sorry for the confusion, where I come from we call these things (literally translated) capital crimes. I guess the proper english word would be a felony that doesn't involve hurting someone else physically (e.g. robbery, tax evasion, theft etc.)