For stealing $300, no, I would not agree to changing the law to allow a shooting. Theft is not a capital offense.
For armed robbery, however, I would be willing to change the law to allow a back shot. Off-the-cuff thinking anyway. I think police can use lethal force to apprehend a violent felon dangerous to the community. I would have to look it up. I vaguely recall that
Tennessee vs Garner might have said
"immeninent threat to the community." In any event, whatever the police are empowered to do, I would be inclined toward not witholding that power from the citizens who gave it to the police in the first place.
ETA: I found
Tennessee vs Garner.
Where the suspect poses no immediate threat to the officer and no threat to others, the harm resulting from failing to apprehend him does not justify the use of deadly force to do so...
...Where the officer has probable cause to believe that the suspect poses a threat of serious physical harm, either to the officer or to others, it is not constitutionally unreasonable to prevent escape by using deadly force. Thus, if the suspect threatens the officer with a weapon or there is probable cause to believe that he has committed a crime involving the infliction or threatened infliction of serious physical harm, deadly force may be used if necessary to prevent escape, and if, where feasible, some warning has been given...
http://supreme.justia.com/cases/federal/us/471/1/case.html
You know, on the surface it seems the court couldn't make up its mind. In the first sentence it uses the word immediate. But in the second it changes its tune.
So, at the moment, subject to further consideration, I would say let the robbery victim shoot the fleeing dangerous felon to apprehend him. I'll think on it some more to see what ramifications come to mind.
Side Note: Notice that the ivory tower justices practically erased the old common law doctrine that a burglary after dark was a violent crime. For space reasons I won't go into why it was considered a violent crime at one time, and probably still is in some places. Let me just say the reasoning for considering nightime burglary a violent crime was sound. Yet, the court just erased hundreds of years of common law tradition in one or two sentences. Moreover, the court even cited that the FBI classifies burglary as a property crime. Oh, great! An FBI bureaucrat can change 700 years of common law heritage! And, SCOTUS will use it as an excuse to bolster its argument! Great! Just ****ing geat!