Man approached me in parking garage where woman was stabbed last week; I back away, he keeps coming

I needed some prescriptions before surgery next week, was near the hospital, decided to stop in & see if their pharmacy had what I needed (instead of going across the city to my regular pharmacy). In the parking garage, I saw a car parked on the lowest ramp, next to the exiting traffic (in its own area, not the driving lane). No signs about "employees only" or "no parking", so I parked there too. After I'd gotten out & closed/locked my door, a guy came toward me & was sort of shouting. He looks like he has an ID tag around his neck, but criminals do use pretenses, right?He was maybe 40' away when I could make out that he didn't want me to park there, something about that was only for the woman who works at the front desk. As he kept coming, I backed off a bit, told him I was going to the pharmacy (had the prescriptions in hand), didn't see any signs prohibiting parking.He kept coming, repeated what he'd already said, so I backed off some more & unzipped the compartment in my purse which holds my pistol, put my hand on the grip. When he got within maybe 10' (and I was still backing away) he finally realized I was alarmed & treating him as a threat, so he stopped. Said it was OK to park there for now, but next time park out front (in the pickup/dropoff area, where there are 'no parking' signs).I agreed to move, waited until he'd walked away, got back in the car, parked out front. How much of an idiot do you have to be to do this, ESPECIALLY when just the week before a woman was seriously injured in that very parking garage?!(Yes, the hospital is a "gun-free" zone, and they even try to prohibit all 'weapons' on their property, but state law doesn't allow that.) News piece about the attack last week:https://ift.tt/2GH5oX9 via /r/CCW https://ift.tt/2HgwfGz