Tenn. police looking at revenge as motive; note found with bomb
                                
                                
                                    (Newser) -
                                    The wife of a retired lawyer who was killed by  a mail bomb  this week has also died, reports the  Tennessean . Marion Setzer, 72, had been listed as seriously injured in Monday's explosion. Meanwhile, police trying to get to the bottom of the bombing may have found a vital...