I can see this becoming a major problem in the future so I wanted to have a plan of action.

We used one of our existing local lenders to provide the majority of the purchase, and the rest was provided from our investors.

Check out some of things happening in Detroit in 2024:https://michiganchronicle.com/2024/01/03/major-developments-that-will-define-detroit-in-2024/Your first question shouldn't be WHERE to invest (that is #2 question), but HOW you will invest!

So, here are my questions, if you have time to answer (not in a hurry) Have you seen the price difference between a ghetto and a downtown in any major city? 

The vast majority of these units I purchased using private financing with $0 out of pocket. 

However, in the vast majority of cases they won't even investigate the claims telling the victim to proceed in civil court on their own.

Sometimes these are minor glitches, other times a major “realignment” is necessary.  

Quote from @Caleb Brown: Seller is still paying both sides in the majority of ones.

2 unit house 30 year FHA 6.6% major renovations (roof,bathrooms,kitchen,etc) home has appreciated 397k when appraised to 550k zestimate (similar comps in the area are 500k).

The right property manager will take up majority of the workload for managing tenants / maintenance and everything else.