If it isn't him, then kudos to Public Enemy #1 for never robbing another bank or killing another LEO or civilian for the rest of his natural life....
I think he was dead within 30 days of the G-Men ventilating the wrong guy outside the theater. Ain't no way in hell Dillinger would have stayed quiet. He got smoked shortly after the shooting at the theater. Hoover would've killed a whole town to make sure the secret stayed secret. The G-Men either smoked him and threw him in a hole or Machine Gun Kelly getting killed was actually Dillinger. I know it sounds conspiratorial, but today's FBI will still circle the wagons to protect Hoover.