She may have tapped the trunk of the car to let them know she was there so as not to startle them. If so she didn’t count on one of them being a paranoid lunatic.
Good Point Tiger’s Eye
Good point-—she tapped to alert them to the fact she was approaching. She did not realize that commonsense would dictate that one approaches someone in that situation from the front, well from the front, hands positioned to demonstrate they aren’t possibly holding or near a weapon. Heck I do that latter if I get pulled over for a traffic stop.
She may have just been too naive to the world or to inner city USA and it never occurred to her that streets there and elsewhere are battle zones where one must realize you are not ASSUMED to be benign, you are rather assumed to be a threat. Still absolutely not an excuse.
I stick with this: Dude was TRIGGERED by scantily clad white committing blasphemy against Allah, disrespecting a Muslim man, etc. He instinctively killed her just as he would instinctively throw a rock at the head of a buried woman who’d shown her ankle in public in his area of the world.