Board Thread:Questions and Answers/@comment-24520051-20171203215353/@comment-1257201-20180516214047

The graduation need not be shown, but it has to be at least mentioned. So the Earth-Two Dick Grayson doesn't count, because we can only infer that he graduated; it's at least theoretically possible that he took some kind of high-school equivalency test before going on to law school.

The first Earth-One Dick Grayson did graduate in the comics, so he qualifies -- but he wasn't the first.