Finding previous owners that have packed up and left, best strategy for getting

Finding previous owners that have packed up and left, what would be the best strategy for getting something going on these properties. I have asked only one neighbor so far if they had any info on the family, but she did not have a number for the family, but she did tell me that the family had abruptly left in the middle of the night some 9 months ago. The name I retrieved from the appraisal districts site gave me only a name, reverse address rendered nothing so far. A sign on a window restricting entry to protect the interest of the lender,[then goes on to say BAC field Services Corp ( New company Bank of America formed after being busted by 60 minutes for forging notary signatures and assignments of mortgages and other important ownership docs. This program is a must watch. {http://www.cbsnews.com/video/watch/?id=7361572n)] The sign says that BAC does not own the property and that all inquiries need to be addressed by a real-tor. If there is no mortgage company what would be the best course of action. Thanks