Arizona/New Mexico Investors-- locating illusive sellers

Greetings!

We are located in Arizona, where there are a lot of homes that have been bought and later abandoned by people who are oftimes here illegally. We are trying to figure out how to locate those sellers. Have any of you run across this problem, and if so, how have you dealt with it? Any suggestions on finding people who don’t want to be found or don’t have the ususal “history”? :banghead:

Thanks.
sixdirections