fuagf -- what happened at/in the police car would/could bear on whether the shot (or shots) fired at that point was (were) justified -- if the cop's claim that Brown was trying to grab his gun were true, then at that point . . .
as for the grounds for the cop legally killing another, haven't gone to look up an exact answer (wasn't my area of practice), but your summary there is at least generally on the mark
Market Data 
Markets 
AI
