Finding out who is actually the seller of a proptery

[David Rhodes]

I'm out and about everyday. While I am driving I'm stopping at homes that have posting in the front windows. It's obvious that the owners have long gone. When I try to find out who the mortgage company may be I run into a wall and it has not made it to the MLS listings. Is there a way to find out who holds the responsibility for the property so that I can approach them with a possible offer? Any comments will be appreciated.