I've been fascinated with the Zodiac case for years, bums me out he's never been caught.
I think the only chance of finding out out who he was (I think he's dead) is through Familial DNA or a really long shot scenario where a family member (assuming he had any kids or other family to care) finds a box of his stuff and inside is the torn shirt of the cab driver and crazy costume he wore when he attacked that couple at Lake Berryessa AND the family member is familiar enough with the case to recognize their importance (likely trashed a long time ago).