... I just don't get this special categorization of "senior citizens" or "the elderly" when it comes to legal matters.
I understand "senior discounts." Americans over 65 have lower mean and median incomes than Americans between 35 and 65, but presumably more of those incomes are "disposable." Hopefully their homes are paid off (they have higher net worth than other age demographics due to home equity), they're no longer raising kids, putting lots of miles on a car is optional instead of a matter of getting to work, etc. Businesses want that money, so 10% off at the buffet or whatever makes sense (especially since people eat less as they get older).
But I occasionally come across stories like "Houston-area woman arrested for allegedly using pepper spray on 80-year-old man," in which an alleged assailant is charged with e.g. "injury to an elderly person."
Why on earth would aggression against an 80-year-old be considered worse than aggression against, say, a 53-year-old? The couple who reported the attack were presumably not disabled. They were out and about in a car, anyway.
I can understand the "particularly vulnerable" category as an "aggravating factor" in aggression. That is, I can see why people would find it more morally repugnant to attack a baby in a stroller or a stroke victim paralyzed in a hospital bed than to attack an able-bodied adult. But that doesn't seem to have been the case here. Just being old doesn't mean being "particularly vulnerable." All it means is that the guy managed to avoid coronary arrests and off days at the World Trade Center for 80 years.