I'm sure that angle has been explored, but I'd like to think that as with most suicides, they are found fairly quickly in a familiar place. Considering how close he was to his aunt, I would hate to think that he would kill himself AND do it in a place where he would go undiscovered for so long.
There's literally thousands of possibilities and there's just so little to go on. No witnesses, no evidence found (clothing, etc), just nothing. He may as well have vaporized in that bar, that's how bizarre it is that there seems to be absolutely nothing to give even the faintest idea of what happened to Joey. That's what makes it so frustrating. People don't vanish from a crowded place in an urban setting where people were everywhere - inside, outside....Short North was hardly deserted that night, it was a Friday night and the weather was very mild considering the season.