Yes, this is an area I am investigating.

What else should I investigate, if anything, and who do I contact to do that?

Perhaps.Just to add to what @Tom Gimer: points out, "When the buyer defaults": let's add that the seller can and sometimes does sue the buyer, and sometimes the seller is contacted by an advocacy group or an attorney and the attorney general is notified and if hanky panky is involved it can mean an investigation of bank fraud, wire fraud, violation of the Consumer Protection Act, violation of Dodd- Frank and some state specific charges.

I sat through a 2 hour interview with the IRS criminal investigator its taken almost 3 years but when I asked her point blank.. she was like Nope we don't work on it this long and this hard and let it go. 

When these lenders were investigated; addresses turned out to be phony, licenses when claimed false and virtualy 61 of them wanted up front fees in order to process the loan.

About 90% think tax liens work the same everywhere Has anyone heard “investigate, THEN invest?  

What's really important are these 2 things.1) How much research, work connections and investigating are you personally willing to do in any of these markets? 

They have the authority to receive and investigate rent complaints, issue subpoenas, hold hearings, and order landlords to reduce rents for specific reasons.

Particularly be sure to include your goals for real estate investing so that folks can help you. 2) Follow your favorite forum topics and set up keyword alerts!

Indiana legislature needs to pass laws restricting wholesaling and the attorney general needs to investigate and prosecute all involved.