Ask for examples of deals and then go look at county records to see if they're on title.

Market OverviewThe Los Angeles hospitality market showed strong recovery and growth in Q1 2024, with key performance indicators demonstrating significant improvement from the previous year. The average daily rate (A...

The property is in PG county, MD.

I agree there may be times to lower the rent, but in my cities, county and generally state I have found that to be rare   Other parts of the country have different economic, real estate and supply & demand situations.Ultimately it is the market, laws & condition that determine what rent is appropriate and what the community will accept. 

Just last year I expanded my property portfolio by purchasing a four-plex in Los Angeles County (Inglewood area) and a Single-Family Residence in Riverside County. 

Also, cities and counties are wildly inneficient with this stuff and just because they say you can build an ADU doesn't mean they will actually let you.

Also, if it is legal in your state/county, you need to ask for a higher deposit just to protect yourself in case, he decides to break the lease early a second time.Would I let him back in? 

The Cosigner Agreement states they are financially responsible, all communication will take place through the actual occupants, I don't deal with helicopter parents, they are responsible for payment of rent as well as any cleaning/repairs after termination, etc.Don't forget it's not easy to sue a cosigner if they live in another county.  

Located in Allegheny county, Pennsylvania. 

Specifically Monroe county.