Crime and drugs still an issue, but getting quality tenants has not been a challenge... so far so good.

You have the usual causes like drugs/alcohol problems, mental illness and then you have the working poor who remain homeless.

You will have tenets who destroy your place, use it as a trap house or drug den and will accuse you of being a slumlord no matter what.  

Money became a drug and he continued to chase it.

The AP has to be open, notorious and hostile...those terms have a legal meaning and essentially it is that you as the owner have been fully deprived of your right to the property.Absent those items above, it sounds like at best they have another legal right which is a "prescriptive easement".

I had two problem tenants back to back-one was a long term tenant and I don't know what happened with her (possibly drugs), the other covid hit and her and her husband split up and she got in with some troublemakers who she knew from high school. 

Quote from @Nathan Gesner: Unkempt lawns, trashy or broken down vehicles, mattresses and trash on empty lots, boarded up houses, bars on windows, dealers and hookers on the corners, the lack of stores or gas stations, occupied properties are dilapidated, etc.Or when Google maps shows stuff like this: If those are drug zombies, as they appear to be, that's an "F" class neighborhood where nobody pays rent and structure burnouts are common.

Spain- 15 minute visit with Doctor to get prescription.  

I than thought it was tenants, all the "what if's"; what-if they have a fire, what-if there is a shooting, dead body, drug raid, break-in, squatters, feces art, etc etc etc.....   

They are responsible for AML/KYC check to make sure its not money from some mexican drug lord etc. but if you put in more than the 10% net worth outside your primary thats on you.