It has to be a forcible felony. Robbery is on the list.
The law allows you to meet force with equal force, but puts fairly tight limits on being justified in the use of deadly force.
-- So why would someone trying to beat you up not be shoot-worthy when it is if they also try to take your wallet or sneakers or what not? --
Good question. I don't have a good answer, except the law reflects a policy decision. At the same time, if the beating is of a nature that would put a reasonable person in fear of death or serious injury, then deadly force in response is justified. Being slapped, not justification for a shoot. Overwhelmed with physical force, or the opponent shows a knife or gun, or the beating continues for a length of time, etc. - the judge or jury will decide if it's reasonable to be in fear for your life. There is a recent FL case where a guy was justified in shooting at an adversary who was throwing beer bottles at his head - the throwing was a felony and justified the shoot.
>>There is a recent FL case where a guy was justified in shooting at an adversary who was throwing beer bottles at his head - the throwing was a felony and justified the shoot.<<
As it should be. My husband was on a jury where a cop had a beer bottle thrown at him, and it left him seriously brain damaged.