If it has not yet been foreclosed upon then the "previous" owner is still the current and legal owner of the property. Unfortunately even if they are in the pre-foreclosure and/or foreclosure stage and/or the property is either in bad shape or even abandoned, they do not have to sell it to you. They can just wait until the bank proceeds with the foreclosure and takes back ownership. If and when that happens, the bank will list it with a broker and it will be for sale. In the meantime, even if you were to get in touch with the owner, they would have to see if their lender or lenders will allow the home to be short sold (short sale). Without the help of a local real estate agent and/or attorney experienced in short sales, the owner may probably not even be able to make any agreement with the bank to short sell the property.
With all that being said and I do understand your position but I also understand the position of the current owners who probably do not want to deal with you, investors, companies promising to bail them out of foreclosure, their own lender, etc. The worse thing to do when facing foreclosure is stick your head in the sand but unfortunately many people do so.