On multiple occasions, caught on video, the robber says "I got my strap on, don't make me use it", which constitutes a threat of severe bodily injury or death to the proprietors.
This would be considered slam-dunk self defense, and commendable that the proprietor did not actually kill the suspect while defending themselves, in many states.
In some states, lethal force would be justifiable under the law.
One more reason I won't set foot in California.