I'm trying to think if any presidential assassin - would-be or successful - has ever been released from prison before now. Obviously not Booth or Oswald. Leon Czolgosz was executed. Of course, all of the above did succeed in their diabolical quests. John Hinckley is the only man who ever shot a president and failed to kill him. Hombres don't come any tougher than Ronald Reagan.
And Hinckley is now the only man to shoot a president and eventually walk out of prison, thanks to a Clinton-appointed federal judge who sees no further reason to keep him locked up: