One of two things, maybe some of both.
Either media stupidity and hype, or there is more to the story.
For example, catching the victim at a stop light like that is one method used in many professional hits in other country's.
Columbia for example was famous for 2 guys on a motor cycle, front guy drives rear guy is shooter then they zip off in traffic where a car cannot follow.
From what I've been seeing in the paper this woman got whacked because some one was mad at her, or mistook her for some one else. If you get paid, and I doubt very much the shooter was the one mad at her, that makes you "professional".