Maybe someone can help me with this face to face question.


Today, my brother attempted to sell an AR-15 to another person face to face. They went to our local hardware store that handles FFLs and is also a gun shop. When the dealer did the background check on the party interested in purchasing the AR, it showed there was a protection order from his wife from a number of years ago so he was denied. The dealer told my brother he now couldn't sell the rifle to this individual because he was aware of this information and that he could be culpable in some capacity if a crime was committed by this individual with this weapon in the future. What got me was the dealer told my brother that as a seller you must do your due diligence and make a reasonable effort to make sure whoever is buying a weapon from you has no priors or anything that would prevent them from owning a firearm. I've never heard of anything like that in Pa before for private sales.


My question is:


As a private citizen selling to another private citizen, is there anything I MUST DO when selling a weapon to make sure a buyer is capable of purchasing firearms? In other words, is the onus on me to make a reasonable effort to determine if a buyer would pass a background check?