Some years ago, I went through a weird time where I was carrying a broken retractable fishing pole with me for protection. It was just the pole part, and only like a 1/4" in diameter and would collapse down small enough to fit into a jacket. if needed, it could extend to about 3 feet, and being fiberglass, could smack the shit out of someone. I never got to use it on any real-life adversary, but I think it would probably be more annoying that threatening.
So maybe get something like that, and if it happens next time, just open up and unleash a torrent of blows upon him with this or a tv antenna. a few whaps! whap! whaps! accompanied by screaming in French will surely drive the bastard away.
Did it ever occur to you or the cops that he might have just been the world's most persistent newspaper delivery boy?