Vacant home w/ rumored back taxes...can I make a deal happen, & how?

[Vonetta Booker]

There's a vacant home I came upon while out bike riding in my neighborhood. In great condition as far as vacant homes go; checked on the MLS & it was an expired short sale nearly 5 years ago, with a list price waaay below market in this area. I'm definitely interested.

Knocked on the next door neighbor's door, intro'd myself & asked if he knew about the property.  He said it's bank-owned, lots of people have checked out the house--but there are supposedly a ton of back taxes owed--close to 100k, according to the neighbor.  Said the owner just skipped out & disappeared a while back, leaving the taxes owed. 

On its property card on the city's tax site, the private owner is listed (w/ the same address)--which is why I was initially led to believe it wasn't yet bank-owned.  However, the notice on the door lists a field rep service that's used by a lot of banks.  

What's the best way to go about doing a possible deal? I'm wondering if I'd have better luck contacting the bank listed as holding the mortgage on the last MLS listing, rather than tracking down the previous owner. Also, would the bank be able to tell me how much back taxes are owed, and would that be classified as a tax lien deal? (How do tax lien deals work, anyway?) Would I as the buyer be responsible for the back taxes plus the price of the house?  

Sorry for the long-winded multitude of questions, lol.  But if I can get it at below-market (even to live in first & then rent out later), that would be awesome.