A petition for a writ of error coram nobis or error coram vobis challenges a final judgment in a criminal proceeding. Use of this type of petition varies from jurisdiction to jurisdiction, but is usually limited to situations where it was not possible to raise this issue earlier on direct appeal. These petitions focus on issues outside the original premises of the trial, i.e., issues that require new evidence or those that could not otherwise be raised by direct appeal or writs of cert. These often fall in two logical categories: (1) that the trial lawyer was ineffectual or incompetent or (2) that some constitutional right has been violated.