Authorities have confirmed the identity of the Nashville bomber -- it's who everyone thought it might be, and his fate is also sealed ... the guy's a goner.

The U.S. Attorney for Tennessee made the revelation Sunday at a presser, saying 63-year-old Anthony Quinn Warner is, indeed, the man they believe detonated a bomb in an RV that was camped out in front of the AT&T building in downtown Nashville early Christmas morning.

He also said Warner died at the bomb site, and that human tissue discovered -- and later analyzed by the Tennessee Bureau of Investigation -- matched Warner's DNA profile.

As for the RV ... officials say that, too, also belonged to Warner. They linked the VIN number to him. It appears the vehicle had been in his possession for a while, as it had been seen parked at his property as recently as last year. Neighbors also ID'd it in interviews.

Still no word on motive -- although there's speculation he might've been paranoid about 5G tech, but that hasn't been confirmed. The feds also say they can't link his act to any type of ideology they've picked up on in the early days of their investigation. As a result, they aren't dubbing it as terrorism just yet.

Fortunately, Warner himself is the only fatality from the bombing ... which is pretty miraculous considering how big it was. A few people were injured, but not critically.

The moments leading up to the explosion add an extra layer of unease as the why continues to be a mystery ... Warner had an alarm blaring for several minutes telling people to evacuate, and then right before his bomb went off -- cops say he played Petula Clark's "Downtown."

Surrounding businesses were decimated in the blast -- not to mention other damage to public property -- and several shopkeepers are looking for help as they navigate next steps.