Vet the contractor (license, bonded, insured, no criminal history) , do NOT pay them ANYTHING upfront.

Criminals commit crimes. 

He had a criminal history in 1997, ready to give some extra security deposit. 

I have had tenants that have no criminal backgrounds but their work ethic sucked which affected the rent being paid on time.. but that’s just how I see things.

The other end of the spectrum are solo practitioners who usually went to local law schools (much less demanding/competitive), they advertise in the phone book, the name of their firm is usually their own name, and they usually list a long line of things they do--criminal, bankruptcy, traffic accidents, etc.  

Do be careful though , criminals are criminals and they can be devious and dangerous.

Is there any area recommended with low criminal rate and reasonable ROI? 

In addition, you could be criminally charged for fraud.  

I'm not a lawyer, but he executed a self-help eviction without statutory notice.In addition to the 4 criminal charges, I believe his alleged statement "Everything that occurred with this house was lawful" is incorrect.Upshot: Maybe it goes without saying, but don't be like that guy.

The tenant used their own card and falsely disputed the charges later.Ask the tenant to remedy the situation by making payment or you will pursue criminal fraud and civil remedy.