I'd like to know if the clerk who shot the dirtbag had any previous gun knowledge. She took quite a chance grabbing the rifle not knowing if it was loaded, safety on or what. Seems that it happened pretty quick and probably the lead eater was going to shoot them once he had them tied.
I don't think much of those who rob gas stations (or anywhere else), but this guy seemed dumber than most. He put down his gun? And he put it down out of reach? Darwin at work.
It's probably just procedural BS. The DA probably wants to cover their behind. A lot of states have laws in place justifying a standard of investigation any time there's a homicide, even if that homicide is legitimate in the eyes of the law. The fact that it should take a "day or two" though, is pretty stupid.