Other than that, you are into going to the court house and looking for public records or obituaries but they would not give you anything really juicy, just saying ;-)
M&M Real Estate
Some states, like MN, have specific disclosures that are required surrounding deaths in a property. I would recommend that you ask the question of an agent in your state and see if any similar rules exist where you live.
As far as finding people who used to live in your house - you might try looking through your abstract. The owners of the property will be listed there. Failing that your county might have some records you can look into.
#1 Trulia Agent in MN