It looks to me like this girl was a drug mule or something. And despite what the article says, if she stopped in to see Ali, I don't think she was trying to get out. Either she ripped someone off, or there's a rival gang, which no mention is made of.
I think that you are closer to the truth than you know. Something about this whole story is cockeyed and yours is the best angle so far, in as much as she was involved with these people and not on the fringes.
I figure she talked to much...
Burning is an excruciatingly painful way to die. This was a marker laid down as a warning to others. If they wanted her dead, they would have just shot her and been done with it. No, they wanted her to suffer. The gas in the mouth is that she "talked" to someone...