Investigation past history.?

How does someone in Ontario Canada investigate someones personal history.. Past relationships, Marriages, Employment,Litigations for and against, Financial situation ( debts ), Past Addresses.Property owned etc etc...I know due to privacy acts it is harder to do so than in the U.S..Would the best route to go is hire a PI.. The person I am intersted in lives in a city (Oakville) that is 4 hours from me so to do this myself could prove difficult