There are two probabilities, imo. The first, and most likely, is a hired hit. Hired by someone close to her. This is my primary suspicion, due to the time, place, etc., of murder. The garage sale threw things off a bit, in that Sergio left at a slightly different time than normal. It seems highly likely to me that someone knew that Liz would be out there by herself just before daylight.
The other option is the Star Wars angle. People get very wrapped up in this game, and Liz was in a position to decide admissions to the 501 or whatever it was. Or whatever. I can’t remember the exact details now, but she was in some way a decision maker, I believe. She triggered someone in relation to this, and they wanted revenge.
I’d love to know more about the prior incident. If I recall, it happened at work.
And: My understanding is that Sergio, early on, named a name. And I think I’ve recently learned who that name belongs to. Interesting. Remember, these things are usually done by people related, somehow, to the victim.
My bets are on one of these two scenarios, although the first is my number o possibility.