How Can I Find Out If A Property Is Mortgaged?

I believe that there are documents which will prove that the property is mortgaged unless a person mortgaged it without a written agreement. But in that case the property is not mortgaged properly. You consult a good attorney for help under this matter. He is the right person to advise and explain about all the nuances about mortgages and related issues. There would a be lot of legal things concerned with mortgages and no one can be of better help than a lawyer.

But if you have some knowledge about law yourself then you can also try and read about mortgages in property law. But it is complicated stuff and you might not be able to understand everything about it. A person while selling property has to declare and prove that he does not have any previous mortgages or other liabilities.

Assuming you are in the USA-

The fastest way to do it without paying a fee is to go to www.searchsystems.net then choose your state and county.
Another free method is too simply go to your county governments website and follow the links to recorded documents provided you know the owner's name or whatever identifying item the search requires.
If you are located in State that has title insurance companies that offer free customer service like here in Washington State, you can simply call one and ask for the customer service desk, give them the address and get the answer in a few seconds.
Consulting an attorney would be a totally unnecessary expense in the USA because mortgages are essentially ineffective unless perfected by recording and all land recordings are done for the express purpose of serving notice to the public, therefore are available to the public without charge.

All legal mortgages are recorded in the county in which the property is located.  Go to your county auditor. You might have to go to 2 different offices. 1 office to look up the record of the property i.e., the numbers and section etc. Then go to the county recorder and they can tell you if they are any mortgages or liens on the property.  Be sure and ask about the liens, and taxes paid or not paid. If you buy property that has taxes due, you might lose the property by default.

You run a title search on the property to check for any liens against it, a clear title will be enough.

You must run a title search on the property to ensure that there are not outstanding mortgages, as well as outstanding property taxes, leins, ucc's, as well as to make sure the property is not "land locked", which mean than no matter how freely and clearly you owned the property, you could not get to it (no right of way). You could consult an attorney, but you would really be better off with a very reputable title company, as these people do this every day, and are usually much more proficient than an attorney.  Actually, most attorneys hire title companies themselves, and then just charge you double.