He does not have the right to ask in the first place. Any if anyone was beaten to a pulp where is the medical report.
On more than one occasion, I've walked out of my house and tapped on the drivers side window of a car parked across the street, with it's music blaring so loud you can't hear yourself think. When the driver rolls down the window, the first thing I ask him is 'do you live around here.'
There is nothing in the Constitution that prevents me from doing that, and so long as I am acting in a reasonably civil manner, I doubt I would be running afoul of any local or state ordinances.
This is no different in principle from what George Zimmerman did, if indeed he was the first to make contact. Now, you can certainly argue the wisdom of doing such things, but I doubt very much that you can argue it's illegality.
Unless you have a compelling argument that contact between two citizens is, in itself, illegal, then this so called right that you think Mr. Martin has simply doesn't exist.
That said, I'm not about to condemn the man until I know all the facts, or at least a good portion of it.