How can I purchase an abandoned house quickly (more or less)?

There is a house in my mother in laws neighborhood that has been abandoned and through public records and talking to the treasurers department we have found that the title never changed hands and there was never a will or probate established for the property. The owners who passed away around 20 years ago had no heirs (rumor has it there is a great niece or 2nd cousin in Canada but nobody knows for sure). The wife passed away first, the husband remarried but never put his new wife on the title, he may never have had the chance since he passed away only 5 months after remarrying. Anyway the second wife had been renting the house and sort of taking care of it but when she was forced into an assisted living home the house began falling apart. She passed away as well which is what started us down the path of wondering what the deal was with this house. As we understand it we can purchase the tax liens but we don't want to property to sit unattended to for three years while we wait.