"There were a bunch of kids at the house, when Ray got back from a party, who weren't meant to be staying there. They had all been up all night drinking and Barron was one of them," says one source.

LeMoine asked the group to leave and Hilton took exception to it, says the source, asking LeMoine, "'Don't you know who I am? Do you know who my sister is?' .. Barron just snapped at Ray and started pushing him and shouting at him, and that's when Ray hit him."