Presidential hopeful Gov. Mitt Romney yesterday demanded the resignation of his own judicial nominee after she sprang a violent convicted killer over the summer, as new details emerged showing that the judge ignored warnings when she freed the ex-con, now accused of killing a Washington couple. “There was a systematic failure in this case starting with the judge,” Romney’s spokesman, Eric Ferhnstrom, said of Superior Court Judge Kathe Tuttman. “Her decision represented an inexplicable lapse in judgment and was inexcusable. Unless there are facts unknown to us, (former Bay State) Gov. Romney believes Judge Tuttman should resign.” However, a former...