Since when do they have to have a reason?
You can bet your ass this cop is lying his ass off. The woman won’t contest his story now.
all the cop has to do is to say that the woman looked like she could hurt him, or his feelings, and then shot her point blank....that’s the way they do around here...his word against hers...
There are many ways he could have handled this without killing her, shoot out both tires on the drivers side, get her plates, call for backup, etc., etc.
I think she panicked trying to figure out what was happening, especially if doing nothing wrong (easy to understand for a timid, small town woman), rolled up her window out of fear and the idiot cop overreacted 1000%.