The MLS is your best best for small MFHs since that will have the most accurate and up-to-date information.

@Ryan Moyer what dates are you looking?

Send out and post the legal notices and when they expire file for eviction.

If your books are kept up to date and properly maintained you will be able to calculate whichever ROI you are looking to quantify at any time.

So if the listing expired or was unlisted have you pursued out of area properties in areas that you were not familiar with?

What's the best way to find most up to date contact information of the owner?

The industry is also changing fast with new resources and efficiencies coming each year so staying up to date is not going to happen in booksCheck out 300-3000 a podcast by the great guys at Evernest or Property management Mastermind by Brad Larson who is an industry leader.  

Made a full price cash offer before anyone else and set to expire at the end of that same day.

Hello, I am approaching closing date on our first rental property and one of our renovations we are going to do is concrete counter tops.

Some Judgement liens against the owner expire after 5-10 years, if they are not re-recorded.