he was. i didn't know what color he was. and -- and just -- you can see the extraordinary integrity in him. >> lieutenant byrd told nbc's lester holt about the moment he decided to use deadly force. >> we see your arm out there for a considerable amount of time. were you you wavering? >> i was taking a tactical stance. you're ultimately hoping that your commands will be complied with. and unfortunately, they were not. >> reporter: when you fired, what -- what could you see? where were you aiming? >> you are taught to aim for center mass. the subject was sideways, and i could not see her full motion of her hands or anything. um, so i guess her movement, you know, caused the discharge to -- to fall where it did. >> and what did you think this individual was doing at that -- at that moment? >> she was posing a threat to