Geraldo Rivera Says Gabby Petito's Fiance, Brian Laundrie, Should Kill Himself

Brian Laundrie would be better off dead than alive at this point in the Gabby Petito case -- at least that's how Geraldo Rivera feels ... despite there being so many unanswered questions.

The FOX News personality gave us his unfiltered take on the streets of NYC Wednesday when we asked what he made of the saga, and the fact that Brian is still nowhere to be found. In true Geraldo fashion, he did not hold back whatsoever -- he says the dude should off himself.

He's a little flip here, but GR seems to mean what he says ... adding Brian should have some dignity and spare us his hypothetical BS rationale -- assuming he's ultimately charged -- by just drowning himself in a Florida swamp.

Oof ... harsh.

Now, Geraldo does wind it back a little when our photog suggests Brian should give up and turn himself in -- conceding, yes, at the very least. You can tell he's fired up about this story, but there's a major problem with his solution.

It leaves too many loose ends, and wouldn't serve as true justice ... especially not for the Petito family, who are seeking the truth about what happened to Gabby and WHY.