Diy kits are notoriously inaccurate, and typical sit on self dry out and subjective to operator error or recontamination with technical reports made scare you into being manipulated into purchase of some kind.

Under Iowa law, an easement by prescription is created when a person uses another's land under a claim of right or color of title, openly, notoriously, continuously, and hostilely for ten years or more. ...

@Thomas Hatley in Texas, if someone open and notoriously lives and occupies a property, pays  no rent for 10 years, it might just be an open and shut case of adverse possession, you would need to buy the home also from the crazy "tenant" tooand that seller is either also skitzo or more likely just full of bull Might want to check your state laws there where the property is. 

Zillow's estimated values are notoriously inaccurate.

If you have a parent or sibling local to Erie who can assist you from time to time (to show a vacant unit or let a tradesman into a vacant unit) you won't need property management (and Erie is notoriously bad for property management).

Searching his name will tell you if he's opened and closed several companies (bad contractors who get into trouble are notorious for this) which should pop up all the registrations he's made in your state. 

Illinois is notorious for high property taxes. 

Contractors are notoriously busy, and when you have a limited amount of time to turn a unit around (usually two weeks) you can't wait a couple months for projects to be done.

HOA boards can be notoriously incompetent at managing their financials. 

California is notoriously volatile with huge swings in value.