Working retail much of the last 40 years, I will say that the professional classes have been more trouble with outright theft than the poor.
The poor aren't often in a gun store buying up large boxes of ammo, or pilfering thru them to score a handful of bullets. It takes cash flow with a significant disposable element to blow on toys.
It's not grandma on a SS check, or the young guy from the tire shop down the street shoplifting. It's the leisure class who don't punch the clock with nothing better to do - that's today's firearms customer, who owns more than a few guns, and who rifles thru the ammo shelves.
The poor are too busy at the job they have - or helping other family members get to one. The leisure class takes 2 hour lunches and hits a few gun stores to see what might be fun to buy for the next hunting season.
I sell auto parts and my best customers are poor. They have to fix their own cars and are forced to figure out what parts are actually broken before they buy replacements. The well to do come in, buy a complete brake job, have someone else do the work, then refund all the stuff they left sit in the back of their $55,000 diesel truck for a week in the rain. They buy electronic parts, install them, take them back off, and demand a return - which is contrary to federal law. They buy parts for a race car, break noses off of starters with too much timing advance, and demand a warranty replacement.
I can go on - but I'll defer to one more argument. Who gets brought up on charges while in political office, the poor, or professional? California gun runner, anti gun officeholder caught by the TSA? Not poor.
It's not a homeless guy pushing a shopping cart pilfering ammo. It's the professional classes, salaried employees, and tenured who are simply exercising their privileged status in life.
It very much is known to Loss Prevention. They have the video to prove it. White collar crime easily bests blue collar, what we have is a phenomenon where other white collar professionals keep it under wraps. There is at least two cases of embezzlement annually for every bank robbery. The facts are out there, the problem is being willfully informed of them.
Your suburban neighbors are stealing the ammo, not the young mother with two kids living in a shelter.