Common reasons to disqualify a judge include: (1) Personal knowledge of the facts or personal bias. (2) Previous involvement as an attorney. (3) Financial interests in the outcome. (4) A family member has a financial interest in the outcome. The judge has a duty to be informed of any possible basis for disqualification. If adequate grounds exist, the judge must disqualify himself. In federal courts a party must file an affidavit. If the facts in the affidavit are sufficient to disqualify the judge, he must excuse himself and assign the case to another judge. Most states follow the federal procedures for disqualification of a judge. In some states there is an absolute right to disqualify a judge by filing a simple affidavit that there can be no fair trial before that judge.