We like to pay extra-close attention to the properties that are months, weeks, even days away from being lost to back taxes.
This might mean that a tax deed auction is coming up soon and the property is on the tax deed list. Or maybe a tax lien was sold against the property years ago, and now the tax lien investor is foreclosing.
In some states the counties themselves foreclose the property and become the sole owner without an auction of any kind! It doesn't matter how the the system works though, because no matter how it's set up, there's always a "drop dead date" where the current owner will lose the property permanently.
When it's down to a matter of weeks or days until an owner's "drop-dead-date", you will find that the owners have often completely given up on the property - they'll let you have it for just a few bucks to make it worth their time signing it over to you! Why would they do this?
Procrastination. Inheritance. Total Frustration with the Property. Relatives Living in the Property. Laziness. Stupidity.
Often some combination of the above. Even though just a small percentage of the property's value is owed in taxes, the owner cannot come up with the cash (or refuses to pay the taxes any longer), and they've written off the property in their own mind.
You'll be equipped to resell the property immediately, before the tax deadline, and make a nice profit. Or, if you choose, you can redeem the property with your own money and keep it!