Finding the Owner of tax delinquent home

[Evan Kline]

I recently found a house in my neighborhood "driving for dollars." Yard over grown, it's close enough I can keep an eye on it and I haven't seen a car there in the past few months.

My county has pretty immaculate online records if you know where to look. 

I find out the property was purchased for $8,000 (late 80's early 90's, I forget) due to have been paid off in 2004. It was deeded over to the owners two unmarried sons before the father died. One of the sons died in 2012 leaving only one. The public record states the taxable address is the same house, but I really don't think anyone is living there. The living son is in his 70's, I know his name and can't find any record of his death so I'm assuming he is still around, however someone stopped paying taxes on the home in 2010 (before the first sons death) and it's 6 years delinquent, totaling ~$9000 in back taxes. 

I'm going to send a letter to see if someone is checking, or if it's being forwarded elsewhere, but does anyone know of a way to find contact info outside of public records? LinkedIn/Facebook/etc are no goes- this guy is too old to be into that apparently.