I seem to recall on previous posts regarding entry to the USA with a ' record ( we haven't had one of them for a while ) that it was stated that they have refused people even for the fact that they were arrested and not charged
in theory they won't allow arrestees into the USA even if they're found not guilty - or even if they're never actually charged with anything.
But they might let him in after an interview. (No telling with Trump, though; he seems to be encouraging immigration officials to behave even more like immigration officials than usual.)