Many self defense shootings involve no arrest or charges. It depends entirely on how justified the shoot appears when the cops show up. Armed men breaking into your home, mini-mart security camera showing aggressive armed robber - maybe nothing more than a thank you.
Shoot an unarmed kid after the police told you to stay in your car - there'll be legal fees.
Shoot an unarmed kid after the police told you to stay in your car - there'll be legal fees.