IMHO, they had a pre-planed escape and route mapped-out before they killed her. With an escape plan in place, they just waited in the parking lot or wherever for a target of opportunity. I think the killer is not a lone nut. They are hunter killer teams that do this with methodical planning. Shooting people at a distance with no apparent rhyme or reason is difficult things to solve. We can hope they make mistakes and somebody gets a good description that leads to there capture.
Agreed. Could they have small, even residential routes planned out, knowing the major roads will quickly be shut down?