The point I would like to make may or may not fit this particular OP. However, this seems to be an often overlooked case that causes problems between managers and tenants. A tenant within a professionally managed apartment complex could be on unfamiliar ground with both the property and the fair housing laws.
I have in my time rented an apartment to quite a few people who have never before lived in a PPM apartment. These would be tenants who may have rented their home all their lives, but have never before moved into a PPM. These might be people who rented from "Bubba Smith" who owns a couple of rent houses. Bubba comes by once a month to collect the rent, and that's about it. They never lived by rules and regulations, and now that Bubba has kicked them out for the last time, they are at the mercy of the "market". The problem is they still think their PPM apartment is the same deal they had at Bubba's house. The first thing I do when I realize this is the case, is to sit them down and explain they are now going to be renting from a property that is professionally managed and well ordered in it's operation. You then usually get a blank stare, so you have to begin drawing pictures.
I like to use the example of renting a vehicle from a car rental agency. Although many of these people have never done that either, it is a good example of renting by rules and regulations. You have a checklist for the car going out to you, and a close inspection of the car returning to the company. I explain how you need to "walk around" the car looking for damage before you take it out. I explain how you need to watch the miles you rack up while you have the car. I go into detail about how you need to keep it clean on return and full of gas, and how you would be charged a lot of money for any damages. A lot of these people would think you just take the car keys and drive it how you wish, and then simply drop it off when your done. Wrong on car rentals, and just as wrong on apartment rentals.
Sometimes, a little "skoolin" will do a world of good, PRIOR to a move in with some people. In the case of this OP, it might have helped that they KNEW they could not move in someone with a felony, but you see at old "Bubba,s house", well Bubba could have cared less what they did.