Even if it was a known murderer, there is zero practical reason to engage in a projected car chase.
Not to mention, why do we need armed militia to enforce traffic laws? you know, the thing that usually has a maximum penalty in the hundreds of dollars? These aren't even real crimes! Somehow we figured out that parking meters don't need guns or tasers, but why did we stop there?
Please stop trying to force Sanderson to write a series his style would be horrible at and that he would not enjoy finishing.
Joe Abercrombie and Robin Hobb are still alive, among plenty of other excellent grimdark fantasy authors, if you must insist on naming a successor.