For what? If they saw her without a seatbelt (which she admitted) they can stop her. They did. If the police knew of her conviction, that would have explained why they reacted so seriously to a seatbelt violation case. I am not trying to justify the window breaking, tasering, etc....I don't know enough to evaluate that.
I'm just putting additional information out there that may have contributed to the situation.
And again, we put armed law enforcement officers in conflict with civilians over things that should be personal business.
Whether it is about the buckling of a seatbelt or substances they put in their body, it's not about them doing harm to others, wreckless driving, etc.
The legislators created the potential for the scenario. Probably both cops and civilians made some mistakes, as people will do. It is a much larger mistake to set these situations up through laws that control every aspect of people's behavior.