I've been thinking about this now. It is kinda funny, yet lucky (and also logical), how murderers getting caught in connection to a traffic violation is a thing. First that comes to mind is the murderer of
Faith Hedgepeth, who was caught due to a DUI and therefore his DNA entering the system (I am waiting for updates so bad on that one). So now we have BK who seems to think he is oh so smart, but still does not even manage to avoid a seatbelt charge - and even uses that very same car for a murder!
IMO, the common denominator in traffic violations and commiting murder is lack of impulse control (and, often, yes, a certain disregard for rules). One of my professors at uni was doing research on
driving ager/road rage and pointed out, that it is one of those contexts, where it is socially acceptable to lash out at minor details, so it reflects how anger-prone a person is way better than general life-situation surveys, where the social-aceptablity-bias causes people to distort their answers. I feel like this difference in acceptability might be extended to attitude towards law violations (traffic vs other) and maybe even some other aspects, too (someone who steals a bread is seen as a criminal, even in hungry, though frankly, it is not hurting anyone as big stores throw away tonnes of food; while someone driving with a red light is seen as a minor thing, even though you are endagering the lives of others at the sake of your own impatience).
Anyhow, no idea how big of a role that seatbelt charge played in BK getting caught, but it reflects to me that he is so very far from a mastermind. I'm still waiting for possible very personal motive regarding one or more of the girls.