They are the ones who will cause trouble for you by complaining to the HOA and the police.

The funny part of the story is they hired a private eye and got the police looking for the bookkeeper, who was there when I installed the software so I know him by sight.

Sharad has some particularly good tips on identifying what neighborhoods you would want to invest in and checking in with the local police department duty sergeant with respect to crime statistics and desirability of areas. 

Post the fraud wire transfer, I filed a report with the FBI and the local police.

Had to call 911 and EMT, police and fire departments responded. 

He used to manage 70+ properties while working full time as a police detective.

The house has been vacant for a year and a half who knows what else you find (cracked foundation, drugs, look up police acitivity in the area) but if the house gets worse and is condemed by the city for being a hazard to the community he will get basically nothing for it.

And when I do need to analyze a failure, knowing Griffith's crack theory or how hydrogen embrittles polished metal comes in super handy.   

I am fluent in Ukrainian, Russian, English, and Polish and speak some French. 

Did you report this incident to the police?