At the very least you need to hire a title company to run a title search of the title to the property. And be very careful about giving money or valuable items to someone who may or may not own a property - do the search first to make sure this is legitimate.
Robert pointed you in the right direction with the title company. Ensure that the person that actually owns the property is the one you are dealing with - otherwise this turns into a law school hypothetical as someone that lost a lot of money to a bad person.
Best of luck
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You can check the OPA website in Philly, if the property is there. Do a google search, type in the address, and it will tell you the owner. However, as others have clearly stated, get a title search to avoid encumbrances and to verify the true owner.
Definitely check the title. Run a title search. This will let you know who has title to the property, and anyone else who may claim and interest in it via lien, mortgage or otherwise. Also, you should check the local tax office for any outstanding RE taxes. Also, don't forget the issue of realty transfer tax. You should also check to verify what the existing use and occupancy is of the property to make sure you are not inheriting an code violations, specifically an illegal dwelling unit (i.e. legal occupancy is 2 unit building, that was converted without approval to a 3 unit building)
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