a true story: Back in '97, I was standing in line at a bank, a 'guy' was standing at the ATM machine in the lobby, like he was trying to withdraw money. Some guy came toward the bank swinging a money bag ( dumbass ) the 'guy' at the ATM machine wrestled the money bag away from the guy. Now being in business, I frequent this back, ALOT and I know all the tellers, I yelled "robbery in the foyer call the cops" I start running over to try and help the poor idiot, but the robber grabbed the bag and literally ran and dove through an open back window of a POS, multi-colored corona. I also happen to know ALL the cops in this little town, and they ALL KNOW I carry a gun. when Capt'n Frank showed up, he asked me "what happen and why are I involved. I told him what happened and he said "where's your gun and why didn't you shoot him" I said, Capt'n Frank, it was a terrible shoot, there is a Muffler shop 100 yards down range and I didn't see a weapon, If I miss, IM the one in trouble" Capt Frank said - shaking hi head-- "you need more range time, its a felony, like a car jacking, they don't need a weapon ~~~damn it, now we have to chase them, Thanx jmac, you dumbass, then he just smiled and walked away.
So yes, if someone is committing a felony, whether they have a weapon or not, you can legally drop them.
However, be warned. If you do this in a liberal state with a liberal DOJ, you maybe in trouble no matter what. This is why I carry TWO knives. You can figure out the rest