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:

Every adult should be fully screened to ensure you aren't renting to a violent criminal, drug dealer, etc.

I feel like I've dealt with every time crazy situation there is here in Chicago with squatters, evictions, drug dealers, etc., and I still love Cook County because I have a solid team and underwrite deals properly.I think @Paul De Luca nailed it on the head, though - it seems like you are quite risk-adverse, so maybe given your risk tolerance, it's not the best idea, but if it were me, I would not think twice about it, and find a rock start property manager who knows exactly how to vet tenants.

This self claimed "Drug Addict to CEO" doesn't pass the sniff test in my opinion.

Im hoping to find an investor to help me buy the lot next to mine so i can move up from doing tax deeds.. if not i have my next lot picked out and will continue to invest in them while i fix my credit and learn more on investing.. i have always wanted to be successful in life but drugs and bad choices have kept me from it.. now im proud to say there is nothing that will stand in my way of realizing my dreams Just following up.

I'd venture to guess your tenant is a criminal or drug addict of some sort.There's some truth in your thought but he's actually a really nice hard working young man. 

One of the biggest drug dealers in WA state history.

We run a background check to look for drug distribution charges and sex offenders3.

Like deferred maintenance, (bad roof, worn out water heater/AC Unit, warped flooring, water damage) etc, unpaid utilities,  unpaid taxes, a second loan, unpaid HOA fees, a bad pool, bad reputation, sometimes squatters, sometimes they were drug houses, and so on.

Negligent forest management, drug addicts, or illegals?